A group of students observes that a wooden block (m = 0.40 kg) on the end of a string with a radius of 0.7 meters makes 9 rotations in 20.7 seconds when twirled.

Question

What is the block's tangential (linear) speed?

What is the block's angular speed?

Answer 1

tan speed = 2 * π * 0.7 m * 9 / 20.7 = t m/s

ang speed = 2 * π * 9 / 20.7 = a rad/s