Kick Dis Power Puck

Contents

• BODY OF ARTICLE
• REFERENCES
• About the Author
• FIGURES

There is a new toy available that can be used to demonstrate many interesting physics principles. It is called the "Kick Dis Power Puck" and is basically a round plastic hovercraft with a soft cushion material around the perimeter (Fig. 1). It is a product of the Estes Company, which is well known for their model rockets, and is available from advertisers in this journal.^1,2 The puck has a diameter of 19.5 cm and comes in two colors, red or green. The two samples I purchased had masses of 307 g and 303 g, respectively. There is a forceful, built-in fan, which is run by a rechargeable battery and powers the puck for about 30 minutes. A 9-V battery charger completes the package, which sells for about $45.

Figure 1.

When you turn it on, the puck makes a predictable whirring sound not unlike a hair dryer. When placed on a smooth linoleum classroom floor, it hovers motionless with about 2 mm of air between the bottom of the craft and the floor. It is extremely well balanced; if you place a coin on its perimeter, the puck will slowly start to move because more air will escape from one side than the other. If placed on a slight incline, it will predictably gain velocity as it slides down the ramp. This would be an interesting way to illustrate Galileo's famous ball-on-ramp experiment with very little friction.

If two pucks are used, momentum conservation can be illustrated. For example, the bumpers are ideal for observing elastic collisions in two dimensions. To observe inelastic collisions, try placing masking tape around the perimeter of the pucks with the sticky side facing out. When attempting collisions between objects of different masses, I found that I could add about 100 g to a puck before contact with the floor became an issue. If mass is added, it must be mounted evenly around the puck so that it will remain balanced. Otherwise, it will move on its own as mentioned above. Rotational collisions are also possible by spinning one or both pucks before they contact each other.

For quantitative analysis of collisions, I found that a modern digital camera works very well. By placing the camera in movie mode, my camera (Olympus D-510) takes 15 frames per second. If held near the ceiling and aimed toward the floor, a two-dimensional collision can be recorded very easily. Then the digital images can be downloaded to lab computers, where the students can study the frames individually. With an appropriate grid pattern on the floor, the magnitudes and directions of the velocities can be determined.

Using your imagination, I'm sure that you can come up with many more demonstrations or experiments using this versatile and rugged device. Try it. It's fun!

Reference

1. Educational Innovations Inc., 362 Main Ave., Norwalk, CT 06851; http://www.teachersource.com. first citation in article
   
2. PASCO scientific, 10101 Foothills Road, Roseville, CA 95747; http://www.pasco.com. first citation in article
   

John Carlson is an adjunct lecturer in the physics department of Queensborough Community College in New York City. He earned his B.S. degree from Tufts University and his M.S. from Fairfield University.Queensborough Community College, 222-05 56th Ave., Bayside, NY 11364; jcarlson@qcc.cuny.edu.

Full figure

Fig. 1. Power puck on lab table. First citation in article

Up: Issue Table of Contents
Go to: Previous Article | Next Article
Other formats: HTML (smaller files) | PDF (44 kB)