angular displacement

Mar 2009
15
0
New Jersey
Homework question help--

A ball inside a computer mouse has a radius of 1.0 cm. If the mouse moves 12 cm, find the angular displacement of the ball.

Thanks much.
 

physicsquest

PHF Helper
Feb 2009
1,426
474
If the ball revolves once the ball moves a distance = circumference of the ball i.e 2 x pi x 1 = 2 pi cm. So when it travels a distance of 12 cmthe no of revs = 12 / 2 pi times. One revolution corresponds to an angular didplacement of 2 pi radians . So 12 / 2 pi radians will correspond to an angular displacement of (12 / 2 pi ) x 2 pi = 12 radians.