A simple harmonic oscillation experimental device

Abstract

The invention discloses a simple harmonic oscillation experimental device, comprising a cylindrical tube (2) fixed vertically upward at the center of a base (1), a long plate (11) fixed vertically on the outer cylindrical surface of the cylindrical tube (2), a tube cover (7) provided at the upper end of the cylindrical tube (2), a center hole provided on the tube cover (7), a fixed pulley (9) installed on one side of the center hole, a metal ball (3) placed in the cylindrical tube (2), a thin rope (6) at the upper end passing through the center hole on the tube cover (7) and around the fixed pulley (9), and then A slide plate (10) is suspended at the lower end; the interior of the cylinder (2) is filled with liquid, and when the metal ball (3) sinks to the bottom of the cylinder (2) in the liquid, the thin rope (6) pulls the slide plate (10) to move on the long board (11); a slider (13) for fixing a colored pen (12) is placed on the rail surface of a guide rail (4), and the guide rail (4) is placed on the front side of the slide plate (10), and the tip of the colored pen (12) can slide on the slide plate (10), demonstrating the generation process of a simple harmonic oscillation curve.

Description

Technical Field

[0001] The invention relates to a physical experiment device, in particular to a simple harmonic oscillation experiment device. Background Art

[0002] In the teaching of middle school physics and university physics, mechanical vibration is learned. Among them, simple harmonic vibration is the most basic and important learning content. It is the focus and difficulty in the teaching process. Making images of objects doing simple harmonic motion through experiments in real time, intuitively and accurately, allowing students to witness the formation process of vibration images with their own eyes, is the most effective teaching method to demonstrate physical laws. It is the most effective way to answer students' question of "Why is the image of simple harmonic vibration a sine curve?" It allows students to better understand the essence of vibration images and lay the foundation for learning related knowledge of mechanical vibration in the future.

[0003] In practical teaching, there are many experimental devices and methods for generating simple harmonic oscillation images. The most commonly used methods are the sand pendulum method for depicting simple harmonic oscillation images and the stroboscopic method for plotting points in a rectangular coordinate system to generate a sinusoidal curve. However, using a sand pendulum to depict simple harmonic oscillation has fundamental flaws. As the sand in the pendulum flows out, the pendulum's center of gravity constantly changes, causing the pendulum length and, consequently, the period of the pendulum, which distorts the simple harmonic oscillation image. Furthermore, the sand in the pendulum often fails to flow smoothly, causing experimental failures and the images drawn by the sand to become rough and fragile, making them difficult to study further. The stroboscopic method also requires high experimental equipment conditions, and the image generation process is not intuitive. In short, many simple harmonic oscillation experimental methods have their own shortcomings, making them difficult to meet teaching requirements. Summary of the Invention

[0004] The present invention aims to provide a simple harmonic oscillation experimental device that solves the problems described in the background art. Specifically, the device directly plots the motion trajectory of an animal undergoing simple harmonic oscillation by directly plotting the relationship between the actual position and time of the object's motion. This intuitively displays the generation process of the simple harmonic oscillation curve, clearly and unambiguously, conforms to the learning patterns of students as they acquire new knowledge, and greatly aids their learning.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A simple harmonic oscillation experimental device, such as Figure 1 As shown, it includes a base 1, a cylindrical tube 2, a metal ball 3, a guide rail 4, a spring 5, a thin rope 6, a tube cover 7, a wire clamp 8, a fixed pulley 9, a skateboard 10, a long board 11, a colored pen 12, and a slider 13.

[0007] The base 1 is in the shape of a metal disc, with a cylindrical tube 2 fixed vertically upward at the center of the base 1, and a long plate 11 fixed vertically on the outer cylindrical surface of the cylindrical tube 2;

[0008] The upper end of the cylindrical cylinder 2 is provided with a cylinder cover 7, the cylinder cover 7 is provided with a center hole, and a fixed pulley 9 is installed on one side of the center hole.

[0009] The metal ball 3 is placed in the cylindrical tube 2, and the upper end of the metal ball 3 is connected to the string 6. The other end of the string 6 passes through the center hole on the tube cover 7 and passes around the fixed pulley 9, and then the lower end is hung with a slide 10;

[0010] The skateboard 10 is a thin plate made of a lightweight material, and a pulley is provided at the bottom of the skateboard 10 so that the skateboard 10 can move smoothly on the long board 11.

[0011] The interior of the cylindrical tube 2 is filled with liquid. When the metal ball 3 sinks to the bottom position of the cylindrical tube 2 in the liquid, the thin rope 6 pulls the slide 10 to move on the long board 11 to the upper part of the long board 11. When the metal ball 3 is at the top position of the cylindrical tube 2, the slide 10 is put back to the bottom position of the long board 11 by the thin rope 6.

[0012] The guide rail 4 is an air cushion guide rail, and the slider 13 is placed on the rail surface of the guide rail 4. The slider 13 is fixed to the two ends of the guide rail 4 by springs 5 ​​at both ends. The colored pen 12 is fixedly installed on the slider 13. The guide rail 4 is placed on the front side of the skateboard 10 and keeps the rail surface parallel to the plane of the skateboard 10. The tip of the colored pen 12 can slide on the skateboard 10.

[0013] The air cushion guide rail is a commonly used instrument in basic physics experiments. It uses a small air source to send compressed air into the inner cavity of the guide rail, and the air is then ejected from the small holes on the surface of the guide rail, forming a very thin air cushion layer between the surface of the guide rail and the inner surface of the slider. The slider 13 floats on the air cushion layer and breaks away from the rail surface, so it can perform almost resistance-free linear motion on the rail surface, greatly reducing the error caused by friction in mechanical experiments and making the experimental results close to the theoretical value.

[0014] The tip of the colored pen 12 is made of soft material.

[0015] The cylindrical tube 2 is a metal tube or a plastic tube, and its height is between 1000-120 cm.

[0016] The cylinder cover 7 is a metal cover, which does not shake when it is sleeved on the upper end of the cylindrical cylinder 2.

[0017] The cylinder cover 7 is provided with a wire clamp 8 .

[0018] The concave groove of the fixed pulley 9 is vertically aligned with the center hole of the cylinder cover 7, so that when the metal ball 3 falls into the bottom of the cylindrical tube 2, the string 6 will not come into contact with the circular hole on the cylinder cover 7. Figure 2 shown.

[0019] From the technical solutions provided by the present invention, it can be seen that the beneficial effects of the simple harmonic oscillation experimental device provided by the embodiment of the present invention are as follows: (1) The motion trajectory of the animal body undergoing simple harmonic oscillation is directly drawn according to the relationship between the actual position and time of the object's motion, and the generation process of the simple harmonic oscillation curve is intuitively displayed, which conforms to the learning rules of students to accept new knowledge and is of great help to students' learning. (2) The motion generated by the skateboard is a real linear uniform motion, the experimental device has a reasonable structure, and the demonstration effect is clear and definite. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic structural diagram of a simple harmonic oscillation experimental device provided in an embodiment of the present invention.

[0021] Figure 2 A schematic diagram of the positional relationship between the fixed pulley and the cylinder cover of a simple harmonic oscillation experimental device provided by an embodiment of the present invention.

[0022] Figure 3 A schematic diagram of the uniform motion principle of a skateboard of a simple harmonic oscillation experimental device provided by an embodiment of the present invention.

[0023] In the picture: 1. base, 2. cylinder, 3. metal ball, 4. guide rail, 5. spring, 6. string, 7. cylinder cover, 8. wire clamp, 9. fixed pulley, 10. skateboard, 11. longboard, 12. colored pen, 13. slider. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0026] 1. Principle of uniform motion of skateboard 11

[0027] like Figure 2 As shown, the metal ball 3 is placed in a cylinder 2 filled with liquid.

[0028] F1 is the resultant force of the upward pull on the metal ball 3, which is in the upward direction and includes the weight of the slide 10 and all the friction resistances such as the movement of the slide 10 and the rotation of the fixed pulley 9.

[0029] F2 includes the viscous resistance of the liquid, the buoyancy of the metal ball 3, and the influence of the throttling area of ​​the annular throttling hole formed by the metal ball 3 and the wall of the cylindrical tube 2 on the movement resistance of the metal ball 3, and the direction is upward.

[0030] The influence of throttling area on the falling of the metal ball: When the metal ball 3 falls, a pressure difference is formed above and below the ball. The size of the pressure difference is proportional to the liquid flow rate of the throttling hole. When the throttling area remains unchanged, the faster the metal ball 3 falls, the greater the liquid flow rate, the greater the pressure on the bottom of the metal ball 3, that is, the greater the resistance to the falling of the metal ball 3.

[0031] F is the weight of the metal ball 3, which is downward.

[0032] The above three forces on the metal ball 3 when falling in the liquid are all in the vertical direction, while the forces on the horizontal direction cancel each other out.

[0033] When F>F1+F2, the metal ball 3 falls faster in the liquid, but the viscous resistance of the liquid in F2 and the resistance formed by the metal ball 3 and the throttling area of ​​the cylindrical tube 2 wall both increase with the increase of the falling speed of the metal ball 3. The metal ball 3 starts to accelerate from rest, and when the falling speed of the metal ball 3 reaches a certain size, the sum of these three forces is equal to zero, that is, F1+F2=F, so the metal ball 3 starts to fall at a uniform speed.

[0034] Falling speed of metal ball 3: The maximum falling speed of metal ball 3, i.e., the uniform linear motion speed of metal ball 3, depends on the difference between F and the sum of F1+F2.

[0035] Therefore, appropriate parameters are selected, such as the weight or diameter of the metal ball 3, the inner diameter of the cylinder 2, the viscosity coefficient of the liquid, the weight of the slide, etc., so that the movement of the metal ball 3 in the cylinder 2 is accelerated in the first short section, and the rest is a uniform fall, and the slide 10 is driven by the fixed pulley 9 to rise at a uniform speed.

[0036] 2. Experimental process

[0037] (1) Place the guide rail 4 in the middle of the front end of the long board 11, and pull the slide 10 to the middle of the long board 11. Adjust the distance between the tip of the colored pen 12 and the slide 10 so that the soft tip of the colored pen 12 just touches the slide 10. Then pull the slide 10 downward to make the metal ball rise to the top of the liquid surface. Clamp the string 6 with the wire clamp 8 to fix the metal ball 3 at the top of the liquid surface.

[0038] (2) Inflate the guide rail 4, and the slider 13 is suspended on the air cushion layer and is out of contact with the rail surface. At this time, adjust the level of the guide rail 4 so that the slider 13 can stay at any position of the guide rail 4 when suspended. Then, fix the two ends of the slider 13 to the two ends of the guide rail 4 respectively through two springs 5.

[0039] (3) Pull the slider 13 to allow it to freely reciprocate on the guide rail 4, that is, the slider 13 performs simple harmonic vibration, and then loosen the wire clamp 8. The metal ball 3 falls along the center of the cylinder 2 in the liquid, and the slide plate 10 is pulled upward by the thin rope 6 passing around the fixed pulley 9. At the beginning, the slide plate 10 accelerates upward. When the falling speed of the metal ball 3 reaches the maximum value, the metal ball 3 begins to perform uniform linear motion downward, driving the slide plate 10 to perform uniform linear motion upward. When the slide plate 10 passes through the slider performing simple harmonic vibration, the tip of the colored pen 12 draws a trajectory curve of the moving object slider 13 changing with time on the slide plate 10.

[0040] The graph clearly shows that as the slide accelerates upward, the period of the sine curve decreases, and the curve becomes denser. When the slide 10 reaches its maximum upward velocity, i.e., the metal ball 3 reaches its maximum downward velocity and begins to fall at a constant speed, the period of the sine curve is at its minimum, and the density of the curve is at its maximum and remains constant. If you don't want students to see the changing period of the sine curve during a demonstration, you can adjust the starting point of the slide 10's upward motion so that the maximum upward motion is reached before the colored pen 12 touches the slide 10. This will result in a regular sine curve with a constant vibration period and uniform density.

[0041] The maximum falling speed of the metal ball 3 mainly depends on the selection of the diameter of the metal ball 3 and the inner diameter of the cylindrical tube 2. When the inner diameter of a certain cylindrical tube 2 is selected, the metal ball 3 of different diameters can be replaced to change the maximum falling speed of the metal ball 3, and then change the uniform motion speed of the slide to adapt to the experimental requirements of different situations.

[0042] As a student demonstration experiment, the device should not be too high for easy carrying and observation, so the height of the cylindrical tube 2 can be selected between 100-120cm to meet the requirements.

[0043] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in the present invention should be covered by the scope of protection of the present invention.

Claims

1. A simple harmonic oscillation experimental device, comprising a base (1), a cylindrical tube (2), a metal ball (3), a guide rail (4), a spring (5), a thin rope (6), a tube cover (7), a fixed pulley (9), a slide (10), a long board (11), a colored pen (12), and a slider (13); The base (1) is in the shape of a metal disc, the center of the base (1) is fixed vertically upward to the cylindrical tube (2), and the long plate (11) is fixed vertically on the outer cylindrical surface of the cylindrical tube (2); The upper end of the cylindrical cylinder (2) is provided with a cylinder cover (7), the cylinder cover (7) is provided with a center hole, and a fixed pulley (9) is installed on one side of the center hole; The metal ball (3) is placed in the cylindrical tube (2), the upper end of the metal ball (3) is connected to a thin rope (6), the other end of the thin rope (6) passes through the center hole on the tube cover (7) and passes around the fixed pulley (9), and then the lower end is hung with a slide plate (10); The interior of the cylindrical tube (2) is filled with liquid. When the metal ball (3) sinks to the bottom of the cylindrical tube (2) in the liquid, the thin rope (6) pulls the slide plate (10) to move on the long board (11) to the upper part of the long board (11). When the metal ball (3) is at the top of the cylindrical tube (2), the slide plate (10) is put back to the bottom of the long board (11) by the thin rope (6); The guide rail (4) is an air cushion guide rail, a slider (13) is placed on the rail surface of the guide rail (4), and the slider (13) and the two ends of the guide rail (4) are fixed by springs (5), a colored pen (12) is fixedly installed on the slider (13), the guide rail (4) is placed on the front side of the slide plate (10) and keeps the rail surface parallel to the plane of the slide plate (10), and the tip of the colored pen (12) can slide on the slide plate (10).

2. A simple harmonic oscillation experimental device according to claim 1, characterized in that: The slide plate (10) is a thin plate made of a light material, and a pulley is provided at the bottom of the slide plate (10), so that the slide plate (10) can move smoothly on the long board (11).

3. A simple harmonic oscillation experimental device according to claim 1, characterized in that: The tip of the colored pen (12) is made of soft material.

4. A simple harmonic oscillation experimental device according to claim 1, characterized in that: The cylindrical tube (2) is a metal tube or a plastic tube, and has a height between 100 and 120 cm.

5. The simple harmonic oscillation experimental device according to claim 1, characterized in that: The cylinder cover (7) is a metal cover, which does not shake when it is sleeved on the upper end of the cylindrical cylinder (2).

6. The simple harmonic oscillation experimental device according to claim 1, characterized in that: The cylinder cover (7) is provided with a wire clamp (8).

7. The simple harmonic oscillation experimental device according to claim 1, characterized in that: The concave wheel groove of the fixed pulley (9) is vertically aligned with the central hole of the cylinder cover (7), so that when the metal ball (3) falls into the bottom of the cylindrical cylinder (2), the thin rope (6) will not contact the circular hole of the cylinder cover (7).

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