Question

A Stone weighing 1/2 kg is tied to a string 1/2 m long having withstand capacity of 20 kg. The stone is in horizontal circular motion over a frictionless table with a speed of 1.5 ms^-1. If tension in the string, is equal to the breaking force of the spring, the speed attained is

• A. 14 ms^-1
• B. 11 ms^-1
• C. 24 ms^-1
• D. 17ms^-1

Answer 1

Answer: (A)

14 ms^-1

Answer 2

Here, 20 × 9.8 = $\frac { \mathrm { mv } ^ { 2 } } { \mathrm { r } }$ = 20 × 9.8

or v = $\sqrt { 20 \times 9.8 }$ = 14 ms^-1