Question

A body of mass 2 kg attach at one end of the light string is rotated along a vertical circle of radius 2 m. If the string can with stand a maximum tension of 140.6 N, the maximum speed with which the stone can be rotated is

• A. 22 m/s
• B. 44 m/s
• C. 33 m/s
• D. 11 m/s

Answer 1

Answer: (D)

11 m/s

Given,

$T=140.6N$

$m=2kg$

$r=2m$

Here we have to find velocity,

$T-mg=\frac{m{v}^2}{r}$

$⟹\frac{(T-mg)r}{m}=v^2$

That is,

$v^2=\frac{(140.6-2(9.8\left)\right)2}{2}=121$

$v=\sqrt{121}=11m/s$