Projectile motion law demonstration teaching aid

Abstract

The projectile motion law demonstration teaching aid comprises a base, a sliding rod, a locking mechanism, a manual trigger, a first small ball and a second small ball, the sliding rod can be installed above the base in a front-back moving mode, a first magnetic block and a push block are fixed to the bottom of the sliding rod and arranged below the base respectively, and the first magnetic block and the push block are connected with the locking mechanism. A check block and a second magnetic block are fixed to the bottom of the base, the first magnetic block is used for magnetically attracting the first small ball, the second magnetic block is used for magnetically attracting the second small ball, the check block is used for making contact with the front end of the magnetically-attracted first small ball for limiting, the push block is used for making contact with the rear end of the magnetically-attracted second small ball for limiting, and the locking mechanism is used for locking the sliding rod to the base. And the manual trigger is used for unlocking the sliding rod by the locking mechanism and driving the sliding rod. The teaching aid adopts pure mechanical design, is simple and ingenious in structure, does not need a power supply, is green and environment-friendly, is excellent in operability, practicability, heuristic and interestingness, is low in manufacturing cost, is convenient to carry, and can be flexibly applied to various indoor and outdoor demonstration scenes.

Description

TECHNICAL FIELD

[0001] The utility model relates to a physical experiment teaching aid, in particular to a demonstration teaching aid for the law of projectile motion. BACKGROUND

[0002] Projectile motion is one of the important knowledge points in high school physics courses. Projectile motion refers to the motion of an object thrown into the air with a certain initial velocity, under the action of gravity only. According to the different directions of the initial velocity when thrown, the projectile motion of the object can be divided into horizontal projectile motion, oblique projectile motion, vertical projectile motion, etc. Projectile motion is usually used to introduce and discuss the basic concepts of force and motion, especially the application of Newton's law of motion. Through the study of projectile motion, students can understand how to analyze the motion of an object in two-dimensional space, including horizontal uniform motion and vertical motion affected by gravity.

[0003] The existing projectile motion demonstration teaching aid has the problems of complex structure, high cost, limited use occasions, etc. For example, CN108877417A discloses a physical teaching aid for horizontal projectile motion demonstration, which comprises a base, a lifting assembly, a horizontal throwing assembly and a demonstration board. The lifting assembly is arranged at the left end of the base, the horizontal throwing assembly comprises a horizontal plate, an electric push rod and a first small ball, the left end of the horizontal plate is connected to the lifting assembly, a horizontal slide is arranged on the horizontal plate, the electric push rod is arranged at the left end of the horizontal slide, the extension end of the electric push rod extends to the right and is connected to a push plate, the first small ball is arranged in the horizontal slide, and the push plate pushes the small ball to move along the horizontal slide. The demonstration board is arranged at the right end of the base, the demonstration board is provided with grid lines, and the right end of the demonstration board is provided with a baffle. The bottom of the demonstration board is provided with a back-rolling slide. The base is provided with a partition plate at the outlet end of the back-rolling slide, the partition plate is inserted into the slot on the base, and the bottom end of the partition plate is connected to the bottom of the slot through a spring. The right end of the horizontal plate is aligned with the right end of the partition plate. This teaching aid needs to use components such as motor, electric push rod, screw rod and screw nut, which has high cost, complex overall structure, is heavy, and has single function, can only realize horizontal projectile motion, and cannot demonstrate oblique projectile motion, vertical projectile motion, etc., so the use occasions are limited. UTILITY MODEL CONTENT

[0004] The utility model solves the technical problems of the prior art, provides a demonstration teaching aid for the law of projectile motion, which adopts pure mechanical design, has simple and ingenious structure, does not need power supply, is green and environmentally friendly, has good operability, practicality, inspiration and interest, has low manufacturing cost, is convenient to carry, and can be flexibly applied to various indoor and outdoor demonstration scenes.

[0005] The utility model discloses a technology scheme for solving the above technical problems, a projectile motion law demonstration teaching aid, including base, slide rod, locking mechanism, hand trigger, first small ball and second small ball, the slide rod be movablely installed in the top of base, the bottom of slide rod is fixed with first magnetic block and push block in front and back interval, first magnetic block with push block set in the below of base respectively, the bottom of base is fixed with stop block and second magnetic block in front and back interval, first magnetic block is used for magnetic attraction first small ball, second magnetic block is used for magnetic attraction second small ball, stop block is used for with the front end contact limit of magnetic attraction first small ball, push block is used for with the rear end contact limit of magnetic attraction second small ball, locking mechanism is used for locking slide rod on base, hand trigger is used for canceling the locking of locking mechanism to slide rod and drive slide rod, make push block push second small ball do projectile motion, at the same time, first magnetic block moves forward and separates second small ball, make first small ball do free fall motion, second small ball with first small ball will collide in the air certain point.

[0006] The utility model discloses demonstration teaching aid operation is simple, through cocking hand trigger, can drive slide rod forward, instantaneous synchronous initiation second small ball's projectile motion and first small ball's free fall motion, can realize second small ball and first small ball will collide in the air certain point, to demonstrate projectile motion law directly.

[0007] The utility model discloses demonstration teaching aid adopts pure mechanical design, simple structure, ingenious, need not power, green environmental protection, operability, practicality, inspiration and interest are all good, and production cost is low, convenient to carry, can be flexibly applied to various indoor and outdoor demonstration scene.

[0008] As preferred, the locking mechanism includes a rubber band, a connecting block, a reed, and a lock hook. The connecting block is fixed to the rear side of the slide rod. The connecting block is connected to the base through the rubber band. The front side of the reed is fixed to the connecting block. The rear side of the reed is provided with a positioning hole. The lock hook is fixed to the rear side of the base. The top end of the lock hook is fixed with a plug rod. The bottom of the rear side of the base is fixed with a handle. The hand trigger is rotatably installed on the handle. The top end of the hand trigger is provided with a top head. The top head is below the reed. When the plug rod is inserted into the positioning hole, the slide rod is in a locked state. After cocking the hand trigger, the top head lifts the reed upward, so that the plug rod is separated from the positioning hole. Thus, the slide rod moves forward under the elastic driving of the rubber band, synchronously realizing the projectile motion of the second small ball and the free fall motion of the first small ball. The second small ball and the first small ball will collide in the air at a certain point.

[0009] As preferred, the base is internally provided with a first long hole and a second long hole, the bottom of the slide rod is fixed with a first connecting block and a second connecting block, the first connecting block and the second connecting block are respectively arranged in the first long hole and the second long hole, the first magnetic block is fixed to the bottom of the first connecting block, the push block is fixed to the bottom of the second connecting block, and the top of the stop block is provided with a avoiding hole opposite to the first magnetic block.

[0010] As preferred, the front side and the rear side of the top of the base are respectively provided with a limiting rod, the limiting rod is used for limiting the displacement of the slide rod in the height direction, the overall structure of the demonstration teaching aid is more reliable, and the use effect is ensured.

[0011] As preferred, the first small ball and the second small ball are both small balls made of plastic, and an iron sheet is fixed to each of the first small ball and the second small ball. The small ball can be made of existing table tennis balls, elastic balls and other ready-made small balls on the market, the cost is low, and different color small balls can be selected, so that the demonstration effect is more intuitive.

[0012] Compared with the prior art, the demonstration teaching aid has the following advantages: the demonstration teaching aid is simple and convenient to operate, the slide rod can be driven to move forward by pulling the hand trigger, the second small ball is instantly caused to move in a projectile motion and the first small ball is caused to move in a free fall motion, the second small ball and the first small ball can collide at a certain point in the air, and the projectile motion law is intuitively demonstrated. The demonstration teaching aid is designed by pure mechanics, has a simple and ingenious structure, does not need a power supply, is green and environmentally friendly, has good operability, practicality, inspiration and interest, has low manufacturing cost, is convenient to carry, and can be flexibly applied to various indoor and outdoor demonstration scenes. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is an appearance schematic view of the demonstration teaching aid in the embodiment (the first small ball and the second small ball are in a magnetic attraction state);

[0014] Figure 2 It is an appearance schematic view of the demonstration teaching aid in the embodiment (without the first small ball and the second small ball);

[0015] Figure 3 It is Figure 2 the enlarged view of A in FIG. 1;

[0016] Figure 4 It is Figure 2 the enlarged view of B in FIG. 1;

[0017] Figure 5 It is Figure 2 the enlarged view of C in FIG. 1;

[0018] Figure 6 This is a schematic diagram illustrating the trajectories of the first and second balls during the demonstration.

[0019] The specific reference numerals in the figure are as follows:

[0020] 1-Base, 11-Limiting rod, 12-Stop block, 13-Second magnet, 14-First elongated hole, 15-Second elongated hole, 16-Allowing hole, 2-Slide rod, 21-First magnet, 22-Push block, 23-First connecting block, 24-Second connecting block, 3-Manual trigger, 31-Top head, 41-First ball, 42-Second ball, 51-Rubber band, 52-Connecting block, 53-Spring, 54-Locking hook, 55-Positioning hole, 56-Insertion rod, 6-Handle. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0022] The example teaching aids demonstrating the laws of projectile motion, such as Figures 1-6 As shown, the device includes a base 1, a slide bar 2, a locking mechanism, a manual trigger 3, a first ball 41, and a second ball 42. The slide bar 2 is mounted on top of the base 1 and can move back and forth. Limiting rods 11 are installed on the front and rear sides of the top of the base 1, respectively. The limiting rods 11 are used to limit the displacement of the slide bar 2 in the height direction. A first magnetic block 21 and a push block 22 are fixed at a distance from front to back at the bottom of the slide bar 2. The first magnetic block 21 and the push block 22 are respectively set below the base 1. A stop block 12 and a second magnetic block 13 are fixed at a distance from front to back at the bottom of the base 1. The first magnetic block 21 is used to magnetically attract the first ball 41, and the second magnetic block 13 is used to magnetically attract the second ball 42. The stop block 12 is used to contact and limit the front end of the magnetically attracted first ball 41, and the push block 22 is used to contact and limit the rear end of the magnetically attracted second ball 42. The locking mechanism is used to lock the slide bar 2 on the base 1, and the manual trigger 3 is used to release the locking mechanism from locking the slide bar 2 and drive the slide bar 2.

[0023] In this embodiment, the base 1 is provided with a first elongated hole 14 and a second elongated hole 15. The bottom of the slide rod 2 is fixed with a first connecting block 23 and a second connecting block 24. The first connecting block 23 and the second connecting block 24 are respectively inserted through the first elongated hole 14 and the second elongated hole 15. The first magnetic block 21 is fixed to the bottom of the first connecting block 23, the push block 22 is fixed to the bottom of the second connecting block 24, and the top of the stop block 12 is provided with a clearance hole 16 facing the first magnetic block 21.

[0024] In this embodiment, a piece of sheet metal (not shown in the figure) is fixed on the first ball 41 and the second ball 42 respectively. Both the first ball 41 and the second ball 42 are modified from ping-pong balls.

[0025] In the embodiment, the locking mechanism comprises an elastic band 51, a connecting block 52, a spring leaf 53 and a locking hook 54. The connecting block 52 is fixed to the rear side of the slide rod 2, and the connecting block 52 is connected to the base 1 through the elastic band 51. The front side of the spring leaf 53 is fixed to the connecting block 52, and the rear side of the spring leaf 53 is provided with a positioning hole 55. The locking hook 54 is fixed to the rear side of the base 1, and the top end of the locking hook 54 is fixed with a plug rod 56. The bottom of the rear side of the base 1 is fixed with a handle 6, and the manual trigger 3 is rotatably installed on the handle 6. The top end of the manual trigger 3 is provided with a top head 31, and the top head 31 is located below the spring leaf 53. When the plug rod 56 is inserted into the positioning hole 55, the slide rod 2 is in a locked state. After the manual trigger 3 is pulled, the top head 31 pushes the spring leaf 53 upward, so that the plug rod 56 is separated from the positioning hole 55, and the slide rod 2 moves forward under the elastic driving of the elastic band 51. The push block 22 pushes the second ball 42 to make a projectile motion. At the same time, the first magnetic block 21 moves forward and separates from the second ball 42, so that the first ball 41 makes a free fall motion. The second ball 42 and the first ball 41 will collide at a certain point in the air. Figure 6 The dashed line represents different height positions and motion trajectories of the first ball 41 and the second ball 42.

[0026] The above-mentioned demonstration aid is easy to operate. By pulling the manual trigger 3, the slide rod 2 can be driven to move forward, and the projectile motion of the second ball 42 and the free fall motion of the first ball 41 are instantaneously and synchronously triggered. The demonstration aid adopts a pure mechanical design, and has a simple and ingenious structure. It does not need power supply, is green and environmentally friendly, and has good operability, practicality, inspiration and interest. Moreover, the production cost is low, it is convenient to carry, and it can be flexibly applied to various indoor and outdoor demonstration scenes.

Claims

1. A teaching aid for demonstrating the laws of projectile motion, characterized in that, The application relates to a magnetic ball throwing device, which comprises a base, a slide rod, a locking mechanism, a hand trigger, a first small ball and a second small ball, wherein the slide rod is movably arranged above the base, the bottom of the slide rod is fixed with a first magnetic block and a push block, the first magnetic block and the push block are arranged below the base, the bottom of the base is fixed with a stop block and a second magnetic block, the first magnetic block is used for magnetically attracting the first small ball, the second magnetic block is used for magnetically attracting the second small ball, the stop block is used for limiting the front end of the first small ball, the push block is used for limiting the rear end of the second small ball, the base is provided with a first long slot and a second long slot, the bottom of the slide rod is fixed with a first connecting block and a second connecting block, the first connecting block and the second connecting block are arranged in the first long slot and the second long slot respectively, the first magnetic block is fixed to the bottom of the first connecting block, the push block is fixed to the bottom of the second connecting block, the top of the stop block is provided with a avoiding hole which is opposite to the first magnetic block, the locking mechanism is used for locking the slide rod on the base, the hand trigger is used for unlocking the locking mechanism and driving the slide rod, so that the push block pushes the second small ball to make a projectile motion, at the same time, the first magnetic block moves forward and separates from the second small ball, so that the first small ball makes a free fall motion, and the second small ball and the first small ball collide at a certain point in the air.

2. A projectile motion demonstration teaching aid according to claim 1, wherein The locking mechanism comprises a rubber band, a connecting block, a spring leaf and a lock hook, the connecting block is fixed to the rear side of the slide rod, the connecting block is connected to the base through the rubber band, the front side of the spring leaf is fixed to the connecting block, the rear side of the spring leaf is provided with a positioning hole, the lock hook is fixed to the rear side of the base, the top end of the lock hook is fixed with a inserting rod, the bottom of the rear side of the base is fixed with a handle, the hand trigger is rotatably arranged on the handle, the top end of the hand trigger is provided with a top head, the top head is below the spring leaf, when the inserting rod is inserted into the positioning hole, the slide rod is in a locked state, after the hand trigger is pulled, the top head pushes the spring leaf upward, so that the inserting rod is separated from the positioning hole, and then the slide rod moves forward under the elastic driving of the rubber band, so that the projectile motion of the second small ball and the free fall motion of the first small ball are simultaneously realized.

3. The projectile motion demonstration teaching aid of claim 1, wherein, The front side and the rear side of the top of the base are respectively provided with a limiting rod, and the limiting rod is used for limiting the displacement of the slide rod in the height direction.

4. The projectile motion demonstration kit of claim 1, wherein: The first small ball and the second small ball are both small balls made of plastic, and each of the first small ball and the second small ball is fixed with an iron sheet.

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