Question

You whirl a 32 gram rubber stopper on a string in a horizontal circle above your head. The string has length 82 cm and completes 5 revolutions in 4.1seconds. What is the speed of the stopper in m/s? What is the tension on the string in newtons?

Answer 1

$T=t/n=4.1/5=0.82\ (s)$

$\omega=2\pi/T=2\cdot3.14/0.82=7.66\ (rad/s)$

$v=\omega r=7.66\cdot0.82=6.28\ (m/s)$ . Answer

$F=ma\to F=0.32\cdot6.28^2/0.82=1.54\ (N)$ . Answer