Get Your Science On: Passing on the Right

 In Get Your Science On, Shopcasts and Videos

Check out this awesome experiment made from toy cars and a track. No matter where a car starts on this track, it always takes the same amount of time to reach the end!

What’s Going On

The track is steeper up on top and becomes less steep as closer to the bottom. A car that starts higher has farther to go, but also reaches a faster maximum speed than a car that starts lower on the track. This track follows a special shape called a tautochrone curve; this means that no matter where the car starts, it always takes the same amount of time to reach the end! You may also recognize this shape as a piece of a cycloid, the path made by the outside a wheel is it rolls on level ground.

How to Build

Conor started with a toy car track and built this track incrementally in 3 sections. He used various sized wood blocks to change the steepness of the track sections by moving the wood blocks forwards and backwards to change the track elevation.

1. Starting from the bottom, elevate the first section of track and attach the wood block.
2. Place a second block to elevate the next section of track a bit steeper.
3. Place a car on top the first section of track and a car on top of the second section, and see which one reaches the the bottom first.
4. Adjust the second block as needed. If the lower car reaches the bottom first, the second section must be made steeper. If the higher car reaches the bottom first, the second section is too steep.
5. Repeat this process comparing the 3rd section to the 1st and 2nd sections.
6. Attach all 3 blocks in place.