Question

A mouse is sitting on a record player. The mouse is 10 cm away from the center of the record. The record player plays at 45 rpm (revolutions per minute). The mouse runs in place (its position does not change). How fast must it run

Answer 1

Answer:

       v = 0.4712 m / s       In the opposite direction of the turntable

Explanation:

For this exercise the mouse to remain motionless must run at the same speed as the record player point moves,

Let's use rotational kinematics to find the speed of the record player at the point where the mouse is

          v = w r

Let's reduce the magnitude to the SI system

         w = 45 rpm (2π rad / 1rev) (1 min / 60s) = 4.712 rad / s

         r = 10 cm = 0.10 m

Let's calculate

         v = 4.712 0.10

         v = 0.4712 m / s

In the opposite direction of the turntable