1d60.10: HOWITZER CART

PURPOSE: To demonstrate the independence of velocity components in a dramatic way.

DESCRIPTION: A ball is placed in the launcher and the mechanism is cocked by compressing a spring. The cart is then pushed across the track. At an adjustable point along the track a sensor releases the spring trigger ejecting the ball vertically. Because the ball and the cart both move with the same horizontal speed, the ball stays directly above the cart at all times, and falls back into the launcher. Before doing the experiment, ask your students where the ball will fall: in front, behind, or in the cart.

SUGGESTIONS: Practice is required to get the cart at a constant speed before the cart realeases the ball via the sensor. There are two other ways of doing this demo. You can also place a pully and a mass on the cart. This can then be followed by removing the mass from the cart and then putting the track on a incline.

EQUIPMENT: Howitzer cart with ball on dynamics track, as photographed.

SETUP TIME: 5 Min.

KEYWORDS constant velocity howitzer cart

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