# angular displacement

#### sake

Problem:
[FONT=&quot] [/FONT]The ball in a computer mouse is 2.0 cm in diameter. If you move the mouse 12 cm what is the angular displacement of the ball?

Need help for HW.(Speechless)

#### physicsquest

PHF Helper
The distance divided by the circumference gives the number of revolutions needed to cover that distance. One revolution corresponds to an angular displacement of 2 pi radians. So calculate for the no of revs found as above.

sake

#### angelica

..........................

#### sake

How many revolutions?

#### physicsquest

PHF Helper
When the mouse moves by 12 cm, the ball revolves

(12 / 2 pi x 1 ) times

where 1 = ball radius. One revolution corresponds to 2 pi radians , so the angular displacement is

( 12 / 2pi) x 2 pi = 12 radians.

sake and angelica