Question

A body of mass 90 g is connected to a string of 100 cm length and whirled in a horizontal circle. If the string can withstand a tension of 2.25 N, then permissible maximum velocity of the body is

• A. 2.5 m/s
• B. 5 m/s
• C. 7.5 m/s
• D. 25 m/s

Hint:

In circular motion problems, remember to use the formula for centripetal force and solve for velocity or other unknowns.

Answer 1

The Correct Option is B

The tension in the string provides the centripetal force, which is given by: \[ T = \frac{m v^2}{r} \] where \( T = 2.25 \, \text{N} \), \( m = 90 \, \text{g} = 0.09 \, \text{kg} \), and \( r = 1 \, \text{m} \).
Solving for \( v \): \[ v = \sqrt{\frac{T r}{m}} = \sqrt{\frac{2.25 \times 1}{0.09}} = 5 \, \text{m/s} \]
Thus, the permissible maximum velocity is 5 m/s.