Question

A 1.2 kg rock attached to a string is whirled clockwise in a horizontal circle on a frictionless surface.
The rock moves 8.7 m, moving from point A to point D, and completes five revolutions in a time of 7.2 s.
Determine the magnitude of the force of tension in the string.
SHOW ALL WORK

Answer 1

$$T=m\frac{v^2}{r}=m\frac{s^2(2\pi(n))}{st^2}\\ T=m\frac{2\pi(n)(s)}{t^2}\\ T=(1.2)\frac{2\pi(5)(8.7)}{7.2^2}=6.3\ N$$