Question

A 0.020 rubber stopper is swung in a horizontal circle by 0.80 cm thread that makes 30.0 revolution every 20 seconds.

a.) what is the stopper's speed?

T=?
v=(2pi(r))/T

Answer 1

T=1.5 s?

Answer 2

T (period)
= time/rev
= 20 sec/ 30 rev
= 2/3 sec/rev


ω(angular speed)
=30 rev/20 seconds
=30/20 rev / sec
=30/20*2π radians / s

Velocity
=rω
=0.008m*ω m/s