# 1N30.45 - Inelastic Collision - Speed of a Ball

Code Number:
1N30.45
Demo Title:
Inelastic Collision - Speed of a Ball
Condition:
Good
Principle:
Conservation of Linear Momentum, Impulse
Area of Study:
Mechanics
Equipment:
Balls, Ball Catcher or Box With Crumpled Newspaper, Inclined plane.
Procedure:

Set the inclined plane so that it will shoot the ball into the ball catcher.  The speed of the ball as it leaves the inclined can be calculated by how far the catcher moves on the table after it catches the ball.  Balls of different mass may be used.  The angle of the incline can also be changed.

A less accurate method is to throw a ball into a box of crumpled newspaper.  Measuring how far the box travels will give you a rough estimate of the speed of the ball as it left your hand.  Compare this calculation to the speed measured with a radar gun if possible.

References:
• Edward J. Finn, "Linear Momentum Conservation in a Nonconservative Environment", AJP, Vol. 42, #1, Jan. 1974, p. 54.
• Borislaw Bilash II, David Maiullo, "What's My Speed", A Demo a Day: A Year of Physics Demonstrations, p. 120.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.