Steepest descent line display device

Abstract

The invention relates to the technical field of experimental equipment, and discloses a brachistochrone display device. The brachistochrone display device comprises a device body, the device body comprises a cycloid track, an arc track and a linear track, starting points of the cycloid track, the arc track and the linear track are located at the same height, end points are located at the same height, and height differences exist between the starting points and the end points. The test balls comprise a magnetic ball and a non-magnetic ball and are used for moving along the cycloid track, the arc track and the linear track respectively to carry out brachistochrone experiments. The timing assembly is arranged on the device body and used for timing the movement time of the magnetic ball and the non-magnetic ball along different tracks. The cycloid track, the arc track and the linear track are all conductive and non-magnetic conductive tracks. According to the brachistochrone display device, the conductive non-magnetic guide rail is adopted, the test ball comprises the magnetic ball with magnetism and the non-magnetic ball without magnetism, and the brachistochrone display device can be used for demonstrating the brachistochrone problem under the action of gravity and electromagnetic force at the same time.

Description

Technical Field

[0001] The present application relates to the technical field of experimental equipment, for example, to a fastest descent line display device. Background Art

[0002] In the related art, the fastest descent line demonstrator provided includes a platform, a baffle, a small ball, multiple slides, a photoelectric detector and a digital timing device. The small ball falls in different slides, and the digital timing device records the falling time, so as to demonstrate the existence of the fastest descent line. The current fastest descent line demonstrator uses a steel ball to fall, and the steel ball is only affected by gravity during the falling process, and the scenes that can be demonstrated are relatively simple. Summary of the invention

[0003] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0004] The disclosed embodiment provides a brachistodes curve display device, which can respectively complete the teaching and popular science work of the brachistodes curve problems involving gravity and electromagnetic force, and plays a teaching demonstration and popular science effect on the brachistodes curve problems involving gravity and electromagnetic force.

[0005] In some embodiments, a brachistodes curve display device is provided, comprising: a device body, comprising a cycloidal track, a circular arc track and a straight track, the starting points of the cycloidal track, the circular arc track and the straight track are located at the same height, the end points are located at the same height, and there is a height difference between the starting point and the end point; a test ball, comprising a magnetic ball and a non-magnetic ball, the test ball is used to move along the cycloidal track, the circular arc track and the straight track, respectively, to conduct a brachistodes curve experiment; a timing component, arranged in the device body, the timing component is used to respectively time the movement time of the magnetic ball and the non-magnetic ball along different tracks; wherein the cycloidal track, the circular arc track and the straight track are all conductive non-magnetic tracks.

[0006] Optionally, the magnetic balls include neodymium iron boron magnetic balls, ferrite magnetic balls and / or samarium cobalt magnetic balls.

[0007] Optionally, the conductive non-magnetic track includes a copper track, an aluminum track, a copper alloy track or an aluminum alloy track with conductivity.

[0008] Optionally, the timing component includes: a timing switch, which is arranged on the device body and located at the starting point and end point of the cycloid track, the circular arc track and the straight line track, and is used to generate a timing signal for the movement of the test ball; a timing circuit, which is connected to the timing switch and is used to calculate the movement time of the test ball along different tracks according to the timing signal.

[0009] Optionally, the timing switch includes: a first switch, which is respectively arranged at the starting points of the cycloid track, the circular arc track and the linear track; and a second switch, which is respectively arranged at the end points of the cycloid track, the circular arc track and the linear track.

[0010] Optionally, the first switch includes a photoelectric switch; and the second switch includes a photoelectric switch or a mechanical switch.

[0011] Optionally, the timing circuit includes: a single-chip microcomputer connected to the timing switch; a step-down circuit connected to the single-chip microcomputer, and the step-down circuit is used to be connected to a power supply.

[0012] Optionally, the fastest descent line display device also includes: a display device, which is arranged on the device body and connected to the timing component, and is used to display the movement time of the magnetic ball and the non-magnetic ball along different tracks.

[0013] Optionally, the device body includes: a base, including an installation cavity, the timing component is arranged in the installation cavity, and the end points of the cycloid track, the circular arc track and the linear track are installed on the base; a support frame, arranged on the base, and the starting ends of the cycloid track, the circular arc track and the linear track are installed on the support frame.

[0014] Optionally, the device body further includes: baffles, which are respectively arranged at the terminal ends of the cycloid track, the circular arc track and the linear track, and are used to shield the test ball.

[0015] The fastest descent line display device provided by the embodiment of the present disclosure can achieve the following technical effects:

[0016] The brachistodes demonstration device provided by the present disclosure includes a device body, a test ball and a timing assembly. The device body includes a cycloid track, a circular arc track and a linear track. The starting points of the cycloid track, the circular arc track and the linear track are located at the same height, the end points are located at the same height, and there is a height difference between the starting point and the end point. The test ball includes a magnetic ball and a non-magnetic ball. The test ball is used to move along the cycloid track, the circular arc track and the linear track respectively to conduct the brachistodes experiment. The timing assembly is arranged in the device body, and the timing assembly is used to respectively time the movement time of the magnetic ball and the non-magnetic ball along different tracks. Among them, the cycloid track, the circular arc track and the linear track are all conductive non-magnetic tracks.

[0017] The test rails of the brachistodes demonstration device provided by the present disclosure are all conductive rails, and the test balls include magnetic balls with magnetism and non-magnetic balls without magnetism. During the falling process of the non-magnetic ball along the cycloid track, the circular arc track and the straight track, it is only affected by gravity, which is used to demonstrate the brachistodes problem under the condition of gravity alone. During the falling process of the magnetic ball along the cycloid track, the circular arc track and the straight track, since the cycloid track, the circular arc track and the straight track are all conductive non-magnetic tracks, the magnetic ball is affected by gravity and electromagnetic force at the same time during the falling process due to the existence of electromagnetic induction phenomenon, which is used to demonstrate the brachistodes problem under the action of both gravity and electromagnetic force. Compared with the related art that can only be used to demonstrate the brachistodes problem involving gravity, the present disclosure can not only be used to demonstrate the brachistodes problem involving only gravity, but also to demonstrate the brachistodes problem under the action of both gravity and electromagnetic force. Moreover, unlike the brachistodes problem involving only gravity, the magnetic ball is affected by both gravity and electromagnetic force during its fall, and the force and motion state will change, thereby changing the brachistodes property of the magnetic ball. Demonstration through the brachistodes display device provided by the present invention can enhance the understanding of the brachistodes problem under the combined action of gravity and electromagnetic force.

[0018] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0020] Figure 1 It is a structural schematic diagram of the fastest descent line display device provided by an embodiment of the present disclosure;

[0021] Figure 2 It is a schematic diagram of the structure of a display device of the fastest descent line display device provided in an embodiment of the present disclosure.

[0022] Reference numerals:

[0023] 1 Fastest descent line display device;

[0024] 110 device body; 111 base; 112 support frame; 113 baffle; 114 cycloid track; 115 arc track; 116 linear track;

[0025] 120 test balls;

[0026] 130 timing component; 131 first switch; 132 second switch;

[0027] 140 display device. DETAILED DESCRIPTION

[0028] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0029] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0030] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0031] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0032] Unless otherwise stated, the term "plurality" means two or more.

[0033] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0034] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0035] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0036] In some embodiments, in combination Figure 1 As shown, a brachistodes curve display device 1 is provided, including a device body 110, a test ball 120 and a timing assembly 130. The device body 110 includes a cycloid track 114, a circular track 115 and a linear track 116. The starting points of the cycloid track 114, the circular track 115 and the linear track 116 are located at the same height, the end points are located at the same height, and there is a height difference between the starting point and the end point. The test ball 120 includes a magnetic ball and a non-magnetic ball. The test ball 120 is used to move along the cycloid track 114, the circular track 115 and the linear track 116 respectively to conduct a brachistodes curve experiment. The timing assembly 130 is arranged on the device body 110. The timing assembly 130 is used to respectively time the movement time of the magnetic ball and the non-magnetic ball along different tracks. Among them, the cycloid track 114, the circular track 115 and the linear track 116 are all conductive non-magnetic tracks.

[0037] The test rails of the brachistodes curve display device 1 provided by the present disclosure are all conductive rails, and the test balls 120 include magnetic balls with magnetism and non-magnetic balls without magnetism. During the falling process of the non-magnetic ball along the cycloid track 114, the arc track 115 and the straight track 116, it is only affected by gravity, which is used to demonstrate the brachistodes curve problem under the condition of gravity only. During the falling process of the magnetic ball along the cycloid track 114, the arc track 115 and the straight track 116, since the cycloid track 114, the arc track 115 and the straight track 116 are all conductive non-magnetic tracks, the magnetic ball is affected by gravity and electromagnetic force at the same time during the falling process due to the existence of electromagnetic induction phenomenon, which is used to demonstrate the brachistodes curve problem under the action of both gravity and electromagnetic force. Compared with the related art, which can only be used to demonstrate the brachistodes curve problem including gravity, the present disclosure can not only be used to demonstrate the brachistodes curve problem including only gravity, but also to demonstrate the brachistodes curve problem under the action of both gravity and electromagnetic force. Furthermore, unlike the brachistodes problem involving only gravity, the magnetic ball is affected by both gravity and electromagnetic force during its fall, and the force and motion state will change, thereby changing the brachistodes properties of the magnetic ball. Demonstration through the brachistodes display device 1 provided in the present invention can enhance the understanding of the brachistodes problem under the combined action of gravity and electromagnetic force.

[0038] It should be noted here that the conductive non-magnetic track refers to a track made of metal or alloy that has conductive properties but does not have magnetic properties.

[0039] There are four basic forces in nature: gravity, electromagnetic force, strong interaction force and weak interaction force. Gravity and electromagnetic force belong to the macroscopic scale, while strong interaction force and weak interaction force belong to the microscopic scale. The brachistocentre demonstrator provided in the related art uses a steel ball to demonstrate the fall, and the steel ball is only affected by gravity during the fall. That is, the brachistocentre demonstrator in the related art only considers the gravity problem, and can only show the brachistocentre problem under the action of gravity, without considering whether the brachistocentre problem will be affected in the presence of other forces.

[0040] The brachistocentre display device 1 provided by the present disclosure takes into account whether the brachistocentre problem will be affected by the presence of electromagnetic force. Based on this assumption, the test track adopts a conductive non-magnetic track with conductive material, which are a cycloidal track 114, a circular arc track 115 and a straight track 116. The test ball 120 adds a magnetic ball with magnetism. The permanent magnet magnetic ball provides a magnetic field (magnetic source). When the magnetic ball and the conductive non-magnetic track produce relative motion, eddy currents are generated in the magnetic track. The induced current in the magnetic track interacts with the magnetic field provided by the magnetic ball, and the magnetic track is affected by electromagnetic force; finally, according to Newton's third law, the magnetic ball will also be affected by a Lorentz force of equal magnitude and opposite to the direction of motion of the ball. The specific derivation process is as follows:

[0041] Place the magnetic ball at the starting point of the track. Under the action of gravity, the magnetic ball begins to move along different conductive and non-magnetic tracks.

[0042] The magnetic ball provides a magnetic field (magnetic source): B∝(μ0×m) / R 3 Among them, B is the magnetic induction intensity, μ0 is the vacuum magnetic permeability, m is the magnetic dipole moment, and R is the distance from the magnetic field generated by the magnetic source to the center of the magnetic sphere.

[0043] When the magnetic ball and the conductive non-magnetic track move relative to each other, eddy currents will be generated in the conductive non-magnetic track, following Ohm's law for moving conductors: J = σ(E+v×B), where J is the induced current, σ is the conductivity of the conductive non-magnetic track, E is the electric field strength, and v is the relative movement speed of the magnetic ball and the conductive non-magnetic track.

[0044] The induced current in the conductive non-magnetic track interacts with the magnetic field provided by the magnetic ball, and the conductive non-magnetic track is acted upon by an electromagnetic force (Lorentz force) f: f=J×B.

[0045] According to Newton's third law, the magnetic ball will also be subject to a Lorentz force of equal magnitude and opposite direction to the movement of the magnetic ball. The motion equation of the magnetic ball along the curve is:

[0046]

[0047] Wherein, m is the mass of the magnetic ball, β is the electromagnetic friction coefficient, and α is the inclination angle of the tangent of the curve. For the cycloid track 114, the circular track 115, and the linear track 116, the induced electromotive force generated by electromagnetic induction is different, the electromagnetic force generated is also different, and the brachistocentric descent line properties obtained are also different.

[0048] In the case where the Lorentz force dominates:

[0049] mgsinα=βV

[0050]

[0051] At this time, the expression of the falling time of the magnetic ball becomes:

[0052]

[0053] Let the Euler function be:

[0054] It can be observed that the Euler function does not explicitly contain x, y, and the Euler equation becomes:

[0055]

[0056] It can be concluded that when the Lorentz force is dominant, the brachistocentric descent line of the magnetic ball becomes a straight line.

[0057] Based on the above theoretical derivation, it can be concluded that when only gravity acts, the brachistodes is a cycloid. When the Lorentz force is dominant (much greater than gravity), the brachistodes is a straight line. Under the action of gravity, but when the Lorentz force is not dominant, the brachistodes are between the cycloid and the straight line. From the above analysis, it can be seen that the problem of the brachistodes involving gravity and electromagnetic force is an innovative problem worthy of discussion and demonstration through popular science models.

[0058] Based on this, the brachistocentre demonstration device 1 provided by the present disclosure sets the test rail as a conductive rail with conductive properties, and the test ball 120 includes a magnetic ball with magnetism and a non-magnetic ball without magnetism. The magnetic ball falls along different conductive and non-magnetic tracks to demonstrate the problem of the brachistocentre under the joint action of gravity and electromagnetic force. And the problem of the brachistocentre under the action of gravity alone. This device can be used to be introduced into popular science teaching, so that students can have a better understanding of the problem of the brachistocentre under the joint action of gravity and electromagnetic force through theoretical learning and practical exploration, which plays an important role in improving students' thinking ability and practical ability. In addition, the device is also characterized by reasonable design and convenient application, and has strong intuitiveness and persuasiveness.

[0059] Optionally, the magnetic balls include neodymium iron boron magnetic balls, ferrite magnetic balls and / or samarium cobalt magnetic balls.

[0060] In this embodiment, the magnetic ball is a permanent magnet ball, including but not limited to a neodymium iron boron magnetic ball, a ferrite magnetic ball and / or a samarium cobalt magnetic ball. By using neodymium iron boron magnetic balls, ferrite magnetic balls and / or samarium cobalt magnetic balls, a magnetic field can be provided, and the magnetic neodymium iron boron magnetic balls, ferrite magnetic balls and / or samarium cobalt magnetic balls will produce electromagnetic induction and generate electromagnetic force during the falling movement along the conductive non-magnetic track with conductive properties. In this way, the movement time of the permanent magnet magnetic ball and the non-magnetic ball in different tracks is compared, the problem of the brachistocentre under the combined action of gravity and electromagnetic force is explored, and the problem of the brachistocentre under the combined action of gravity is compared with the problem of the brachistocentre under the combined action of gravity.

[0061] Optionally, the non-magnetic ball includes a steel ball or a plastic ball.

[0062] Optionally, the conductive non-magnetic track includes a copper track, an aluminum track, a copper alloy track or an aluminum alloy track with conductivity.

[0063] In this embodiment, the conductive non-magnetic track includes a metal track or alloy track that has electrical conductivity but does not have magnetic conductivity. The conductive non-magnetic track includes but is not limited to a copper track, an aluminum track, a copper alloy track, or an aluminum alloy track with electrical conductivity. In this way, when the magnetic ball falls along the metal track or alloy track that has electrical conductivity but does not have magnetic conductivity, electromagnetic induction can occur and electromagnetic force can be generated.

[0064] Optionally, when the magnetic ball falls along a metal track or alloy track that has electrical conductivity but no magnetic conductivity, electromagnetic induction can occur, and the magnitude of the electromagnetic force generated is proportional to the electrical conductivity of the conductive non-magnetic track and proportional to the square of the magnetic induction intensity of the magnetic ball. In this way, by using the device disclosed in the present invention, the influence of electromagnetic force on the falling process of the magnetic ball along the conductive non-magnetic track can be demonstrated, so as to intuitively demonstrate the teaching and popular science tasks of the fastest descent line under the action of gravity and electromagnetic force.

[0065] Optionally, the timing assembly 130 includes a timing switch and a timing circuit. The timing switch is disposed on the device body 110, at the starting point and the end point of the cycloid track 114, the arc track 115, and the linear track 116, and is used to generate a timing signal for the movement of the test ball 120. The timing circuit is connected to the timing switch and is used to calculate the movement time of the test ball 120 along different tracks according to the timing signal.

[0066] In this embodiment, the timing switch is used to time the start time of the magnetic ball's movement, and the timing signal of the start movement is sent to the timing circuit. The timing switch is also used to time the end time of the magnetic ball falling to the end point, and the end timing signal is sent to the timing circuit. The timing circuit calculates the movement time of the test ball 120 along different tracks based on the start timing signal of the start movement and the end timing signal of the end movement. By setting the timing switch and the timing circuit, the accuracy of timing the movement time of the test ball 120 along different tracks can be improved.

[0067] Optionally, combined Figure 1 As shown, the timing switch includes: a first switch 131 and a second switch 132. The first switch 131 is respectively arranged at the starting point of the cycloid track 114, the arc track 115 and the linear track 116. The second switch 132 is respectively arranged at the end point of the cycloid track 114, the arc track 115 and the linear track 116.

[0068] In this embodiment, a first switch 131 is set at the starting point of each conductive non-magnetic track, and a second switch 132 is set at the end point of each conductive non-magnetic track. The first switch 131 is used to detect the timing signal of the start movement of the test ball 120. The second switch 132 is used to detect the timing signal of the end movement of the test ball 120. By setting the first switch 131 and the second switch 132 at the starting point and the end point of each conductive guide rail, the accuracy of the timing of the test movement time is improved. Since the first switch 131 and the second switch 132 are respectively set at the starting point and the end point of different tracks, the cycloid track 114, the circular arc track 115 and the straight track 116 can be timed simultaneously or separately, which is convenient for comparing the movement time of the test ball 120 under different tracks.

[0069] Optionally, the first switch 131 includes a photoelectric switch. The second switch 132 includes a photoelectric switch or a mechanical switch.

[0070] In this embodiment, the first switch 131 is a photoelectric switch, which uses the photoelectric effect to trigger a signal immediately when the test ball 120 passes through, with fast response speed and high timing accuracy. The second switch 132 can be a photoelectric switch or a mechanical switch, which provides flexibility. The photoelectric switch also has the characteristics of fast response, while the mechanical switch is more durable and suitable for different experimental environments and needs.

[0071] Optionally, the timing circuit includes: a single chip microcomputer and a step-down circuit, the single chip microcomputer is connected to the timing switch, the step-down circuit is connected to the single chip microcomputer, and the step-down circuit is used to be connected to a power supply.

[0072] In this embodiment, the single-chip microcomputer has a high-precision timing function, which can accurately record the time interval of the test ball 120 passing through the timing switch, ensuring the accuracy of the experimental data. The design of the step-down circuit allows the timing circuit to be connected to power supplies of different voltage levels, ensuring that the single-chip microcomputer and other electronic components can operate at an appropriate voltage and protect the circuit from damage by excessive voltage. In this way, by adopting the step-down circuit, a stable power output can be provided, reducing the impact of power supply fluctuations on timing accuracy, while improving the safety of the entire display device.

[0073] Optionally, the timing component 130 further includes: a battery, a single-chip computer clock, a display circuit, and a debugging circuit. The battery is used to provide power for the entire circuit. The battery is connected to a step-down circuit, and the step-down circuit is used to adjust the voltage provided by the battery to a voltage suitable for the circuit operation. The display circuit is used to display the time calculated by the single-chip computer on the display device 140. The single-chip computer clock is used to provide a timing reference for the single-chip computer. The adjustment circuit is used to adjust and optimize the circuit performance.

[0074] In the process of performing the fastest descent line demonstration using a magnetic ball, the working process of the timing component 130 is as follows:

[0075] The magnetic ball is released from the starting point of each track and passes through the first switch 131 at the starting point. The first switch 131 at the starting point is triggered, and a signal is generated and transmitted to the single chip microcomputer. After receiving the signal, the single chip microcomputer starts timing.

[0076] When the magnetic ball falls along each track and passes the second switch 132 at the end point, the second switch 132 is triggered, a signal is generated and transmitted to the single chip microcomputer, and after the single chip microcomputer receives the signal, the single chip microcomputer timing stops.

[0077] The single chip microcomputer calculates the falling time of the magnetic ball according to the start timing signal and the end timing signal, and transmits the time data to the display circuit, which displays the falling time of the magnetic ball on the display device 140 .

[0078] In the process of performing the fastest descent line demonstration using a non-magnetic ball, the working process of the timing component 130 is as follows:

[0079] The non-magnetic ball is released from the starting point of each track and passes through the first switch 131 at the starting point. The first switch 131 at the starting point is triggered, generates a signal and transmits it to the single chip microcomputer. After receiving the signal, the single chip microcomputer starts timing.

[0080] When the non-magnetic ball falls along each track and passes the second switch 132 at the end point, the second switch 132 is triggered, a signal is generated and transmitted to the single chip microcomputer, and after the single chip microcomputer receives the signal, the single chip microcomputer timing stops.

[0081] The single chip microcomputer calculates the falling time of the non-magnetic ball according to the start timing signal and the end timing signal, and transmits the time data to the display circuit, which displays the falling time of the non-magnetic ball on the display device 140 .

[0082] By comparing the movement time of magnetic and non-magnetic balls in different orbits, the problem of the brachistocentre under the combined action of gravity and electromagnetic force is explored. By comparing with the problem of the brachistocentre under the action of gravity alone, the influence of electromagnetic force on the trajectory and time of the object's movement is analyzed.

[0083] Optionally, combined Figure 2 As shown, the fastest descent line display device 1 further includes: a display device 140. The display device 140 is disposed on the device body 110, connected to the timing component 130, and is used to display the movement time of the magnetic ball and the non-magnetic ball along different tracks.

[0084] In this embodiment, the display device 140 is provided to intuitively display the movement time of the magnetic ball and the non-magnetic ball along different tracks, so that the problem of the brachistocentre under the combined action of gravity and electromagnetic force can be intuitively understood.

[0085] Optionally, combined Figure 1 As shown, the device body 110 includes: a base 111 and a support frame 112. The base 111 includes a mounting cavity, the timing assembly 130 is arranged in the mounting cavity, and the end points of the cycloid track 114, the arc track 115 and the linear track 116 are installed on the base 111. The support frame 112 is arranged on the base 111, and the starting points of the cycloid track 114, the arc track 115 and the linear track 116 are installed on the support frame 112.

[0086] In this embodiment, a base 111 is provided to carry a timing assembly 130 and a test rail. The base 111 is provided with an installation cavity to protect the timing assembly 130, so as to prevent damage to the timing assembly 130 by external factors such as dust and moisture, thereby extending the service life of the assembly. A support frame 112 is provided to support a cycloid track 114, an arc track 115, and a linear track 116, so that there is a relative height between the starting point and the end point of the conductive non-magnetic track to meet the falling motion of the test ball 120.

[0087] Optionally, the base 111 includes a base body and a cover body. The base body includes a mounting cavity, and the cover body is used to open or close the mounting cavity. The cover body is provided to facilitate the installation or replacement of the timing component 130.

[0088] Optionally, combined Figure 1 As shown, the device body 110 further includes baffles 113 , which are respectively arranged at the end points of the cycloid track 114 , the arc track 115 and the linear track 116 , and are used to block the test ball 120 .

[0089] In this embodiment, baffles 113 are respectively provided at the terminal ends of the cycloid track 114, the circular track 115 and the linear track 116, and the baffles 113 are used to block the test ball 120 moving to the terminal end to prevent the test ball 120 from rolling out of the display device.

[0090] Optionally, an extension is provided at the terminal end of the cycloid track 114, the arc track 115 and the linear track 116, and the extension is connected to the terminal end of each track, and the baffle 113 is provided at the end of the extension. The baffle 113 and the extension form a limiting groove. In this way, the test ball 120 rolls into the limiting groove after passing the terminal end of the test track, so as to be used for the next test.

[0091] Optionally, the bottom wall of the limiting groove is lower than the bottom surface of the terminal end of each test track. In this way, the test ball 120 falls into the limiting groove after passing the terminal end, thereby improving the stability of the limiting of the test ball 120.

[0092] In some embodiments, the fastest descending line display device 1 provided in any of the above embodiments is used for experiments. The magnetic balls are tested with ferrite magnetic balls and neodymium iron boron magnetic balls, respectively, and the non-magnetic balls are tested with steel balls. The cycloid track 114, the arc track 115, and the linear track 116 are all made of aluminum tracks.

[0093] Use a steel ball for testing. Since the steel ball is not magnetic, it is only affected by gravity during the falling process.

[0094] Ferrite magnetic balls and neodymium iron boron magnetic balls are used. Since both ferrite magnetic balls and neodymium iron boron magnetic balls are magnetic, they are affected by gravity and electromagnetic force at the same time during the falling process.

[0095] Photoelectric switches are respectively provided at the starting point and the end point of the cycloid track 114, the arc track 115 and the linear track 116 to time the movement time of the steel ball falling along the cycloid track 114, the arc track 115 and the linear track 116, and to time the movement time of the ferrite magnetic ball and the NdFeB magnetic ball falling along the cycloid track 114, the arc track 115 and the linear track 116. The movement time obtained by timing is displayed on the display device 140.

[0096] According to the final movement time, the movement time of the permanent magnet ball and the steel ball in different orbits is compared to explore the problem of the brachistodes curve under the combined action of gravity and electromagnetic force, and compared with the problem of the brachistodes curve containing only gravity. The specific movement time obtained by the experiment is shown in Table 1.

[0097] Table 1

[0098] Time(s) Linear track 116 Arc track 115 Cycloid track 114 Steel Ball 0.60 0.54 0.50 Ferrite Balls 1.16 1.04 1.25 NdFeB magnetic balls 4.31 4.17 5.43

[0099] It can be seen from Table 1 that the falling time of the steel ball along the straight track 116 is 0.6s, the falling time along the arc track 115 is 0.54s, and the falling time along the cycloid track 114 is 0.5s. It can be found that for the falling problem of the steel ball only containing gravity, the falling time of the three tracks in this experiment is from short to long, namely, the cycloid track 114, the arc track 115, and the straight track 116, which demonstrates that the fastest falling line in the classic case of only containing gravity is the cycloid.

[0100] It can be seen from Table 1 that the movement time of the ferrite magnetic ball falling along the straight track 116 is 1.16s, the movement time along the arc track 115 is 1.04s, and the movement time along the cycloid track 114 is 1.25s. The movement time of the NdFeB magnetic ball falling along the straight track 116 is 4.31s, the movement time along the arc track 115 is 4.17s, and the movement time along the cycloid track 114 is 5.43s. It can be found that for the problem of the magnetic ball falling involving electromagnetic force and gravity, the falling time from short to long is the arc track 115, the straight track 116, and the cycloid track 114, and the brachistodes are no longer cycloids, but arcs.

[0101] Furthermore, the diameters of the steel balls, ferrite balls and NdFeB balls used in the experiment shown in this embodiment are all 18 mm. The steel balls have no magnetic field. The magnetic induction intensity provided by the ferrite balls is about 185 mT. The magnetic induction intensity provided by the NdFeB balls is greater than that of the ferrite balls, about 496 mT, which is 2.7 times that of the ferrite balls. The conductivity of the aluminum track is 3.8×10 7 S / m.

[0102] It can be observed that for the same conductive non-magnetic track, the falling time of the magnetic ball is longer than that of the steel ball. For the straight track 116: the falling time of the ferrite magnetic ball becomes about 2 times that of the steel ball; the falling time of the NdFeB magnetic ball with a stronger magnetic field becomes about 7 times that of the steel ball, which is nearly an order of magnitude higher. It can be concluded that the stronger the magnetic induction intensity of the magnetic ball, the longer the falling time of the test ball 120. It can be seen that the brachistodes problem involving gravity and electromagnetic force is very different from the traditional brachistodes problem, and is a problem worthy of teaching and popular science.

[0103] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A fastest descending line display device, characterized in that: include: The device body includes a cycloid track, a circular arc track and a linear track, wherein the starting points of the cycloid track, the circular arc track and the linear track are located at the same height, the end points are located at the same height, and there is a height difference between the starting point and the end point; Test balls, including magnetic balls and non-magnetic balls, are used to move along cycloid tracks, circular arc tracks and linear tracks to conduct the brachistodes test; A timing component, arranged in the device body, for timing the movement time of the magnetic ball and the non-magnetic ball along different tracks respectively; Among them, the cycloid track, circular arc track and straight track are all conductive but non-magnetic tracks.

2. The fastest descent line display device according to claim 1, characterized in that: The magnetic balls include neodymium iron boron magnetic balls, ferrite magnetic balls and / or samarium cobalt magnetic balls.

3. The fastest descent line display device according to claim 1, characterized in that: The conductive non-magnetic rails include copper rails, aluminum rails, copper alloy rails or conductive aluminum alloy rails.

4. The fastest descent line display device according to any one of claims 1 to 3, characterized in that: Timing components include: A timing switch is arranged in the main body of the device, located at the starting point and the end point of the cycloid track, the circular arc track and the linear track, and is used to generate a timing signal for the movement of the test ball; The timing circuit is connected to the timing switch and is used to calculate the movement time of the test ball along different tracks according to the timing signal.

5. The fastest descent line display device according to claim 4, characterized in that: The timer switch includes: The first switch is respectively arranged at the starting points of the cycloid track, the circular arc track and the linear track; The second switches are respectively arranged at the end points of the cycloid track, the circular arc track and the linear track.

6. The fastest descent line display device according to claim 5, characterized in that: The first switch includes a photoelectric switch; The second switch includes a photoelectric switch or a mechanical switch.

7. The fastest descent line display device according to claim 4, characterized in that: The timing circuit includes: A single chip microcomputer is connected to a timing switch; The step-down circuit is connected to the single-chip microcomputer, and the step-down circuit is used to be connected to a power supply.

8. The fastest descent line display device according to any one of claims 1 to 3, characterized in that: Also includes: The display device is arranged on the device body and connected with the timing component, and is used for displaying the movement time of the magnetic ball or the non-magnetic ball along different tracks.

9. The fastest descent line display device according to any one of claims 1 to 3, characterized in that: The device body includes: The base includes a mounting cavity, the timing assembly is arranged in the mounting cavity, and the end points of the cycloid track, the circular arc track and the linear track are installed on the base; The support frame is arranged on the base, and the starting ends of the cycloid track, the circular arc track and the linear track are installed on the support frame.

10. The fastest descent line display device according to any one of claims 1 to 3, characterized in that: The device body also includes: Baffles are respectively arranged at the terminal ends of the cycloid track, the circular arc track and the linear track to shield the test ball.

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