Question

A simple pendulum of length 1 m is initially kept at 60° with the vertical. Minimum speed ‘u’ given to the bob of the pendulum in a direction perpendicular to the string so that it describes complete circle is :

• A. $\sqrt { 5 g }$
• B. $\sqrt { 4 g }$
• C. $2 \sqrt { 3 g }$
• D. $5 \sqrt { g / 3 }$

Answer 1

Answer: (A)

$\sqrt { 5 g }$

Answer 2

μ = $\frac { 2 \mathrm { gh } } { 2 \mathrm { gl } } = \frac { 1.6 } { 3 } = 0.533$