Question

A stone of mass of 16kg is attached to a string 144m long and is whirled in a horizontal circle. The maximum tension the string can withstand is 16 newton. The maximum speed of revolution of the stone without breaking it, will be: 

(A) 20ms^-1 

(B) 16ms^-1 

(C) 14ms^-1 

(D) 12ms^-1

Answer 1

Correct option is (D) 12ms^-1

For circular motion,

Maximum tension = Centripetal force

∴ T = \(\frac{mv^2}r\)

Given, T = 16 N, m = 16 kg, r = 144 m

∴ 16 = \(\frac{16 \times v^2}{144}\)

⇒ v² = 144

⇒ v = 12m/s

Answer 2

Correct answer is (D) 12ms^-1