Question

Two creatures sit on a horizontal frictional rotating platform. The platform rotates at a constant speed. The creatures do not slip off as it rotates.

ASSUME:

Red has a mass of 5 kg

Red is 1.5 m from the center

Red has a speed of 9 m/s

Blue has a mass of 25 kg

Blue has a speed of 1.8 m/s

The force of friction on Red is EQUAL to the force of friction on Blue





DETERMINE:

How far from the center is Blue

Answer 1

M v^2 / R = centripetal force

For Red: M v^2 / R = 5 * 9^2 / 1.5 = 270

For Blue M v^2 / R = 270 = 25 * 1.8^2 / Rb

So Rb = 25 * 1.8^2 / 270 = .3 m