Question

A string under a tension of 50.0 N is used to whirl a
rock in a horizontal circle of radius 2.50 m at a speed of
20.4 m/s. The string is pulled in and the speed of the
rock increases. When the string is 1.00 m long and the
speed of the rock is 51.0 m/s, the string breaks. What is
the breaking strength (in newtons) of the string?

Answer 1

Split into 2 scenarios

1. Fc=T

so find mass using above formula

((mv^2)/r)=T
m=0.3kg


2. Find new tension with new values of velocity and radius and mass

Fc=t
((mv^2)/r)=T
T=780.3