Ballistic Car

This classic ballistic car demonstration delivers the wow-factor that makes abstract physics concepts unforgettable. Using a ballistics car is an excellent way to introduce kids (and maybe even adults) to the concept of relative velocity! Shoot a 25-mm steel ball from a barrel affixed to a moving cart, and watch in amazement as it drops back down into the barrel!

How to do the ballistic car demonstration:

1. Make sure the ballistic car is on a flat, smooth surface
2. Place the steel ball down into the barrel onto the piston
3. Push down on the piston and insert the locking pin into the side of the barrel (try to insert the pin as little as possible to minimize friction)
4. (Optional) Connect a string or cord to the end of the locking pin and hold the string in one hand
5. Use one hand to push the car into motion
6. Once your hand is no longer touching the car, quickly jerk the locking pin (or string connected to the locking pin) out of its hole
7. Watch as the steel ball it launches upwards, and rather than being left behind by the moving car, drops right back into the barrel!

The fact that the steel ball landed back into the barrel proves that while it was launched vertically upwards, it was also moving horizontally at the same speed as the moving ballistic car. Otherwise, the ball would have been left behind and dropped behind the moving car. 

In other words, as elementary, middle school or even high school students observe this ballistic car physics experiment, they will learn that the forward motion (horizontal velocity) of a ball ejected vertically is the same as that of the cart from which it was ejected. 

The barrel on this ballistic car has two spring tension settings, allowing students to experiment with different speeds and launch timing. This physics demonstration comes complete with a 25-mm steel ball and release pin. Let the experimentation fun begin!