The Ballistic Car shows that horizontal motion is unaffected by vertical forces. A spring launcher on a moving cart shoots a ball straight upward; the ball then falls back into the barrel, proving that both cart and ball share the same horizontal velocity.

1. Place a ballistic car on a low-friction track or smooth surface.
2. Load the spring mechanism with a steel ball in the vertical barrel.
3. Push the car gently so it coasts at a steady speed.
4. While the car is in motion, trigger the spring launcher to propel the ball straight upward.
5. Observe that the ball rises and falls back into the barrel while the cart continues moving.

The Ballistics Car—A Classic Demonstration That Still Amazes Students! - Arbor Scientific:

Ballistic Cart Demonstration Video - George Reddick:

📄 Shepard's Crook Pink Ball Release and Catch by Ballistic Cart - Vanderbilt University: https://www.vanderbilt.edu/physicsdemonstration/davesdemos/demonstrations/demo172.htm

• Change the speed of the cart to show the result holds for different horizontal velocities.
• Try launching the ball at rest and compare with launching while moving.
• Use a high-speed camera to analyze the ball’s trajectory in both the lab and cart frames of reference.

• Keep hands clear of the spring mechanism when launching.
• Do not overcompress the spring to avoid damaging the launcher.
• Ensure the track or floor is clear to prevent collisions or tripping hazards.

• Why does the ball land back in the barrel instead of behind the cart? (Because both ball and cart retain the same horizontal velocity.)
• How would the result differ without gravity? (The ball would continue upward indefinitely but still share the cart’s horizontal motion.)
• What principle of motion is illustrated by this demonstration? (The independence of horizontal and vertical motion.)