Question

If a simple pendulum of length L has maximum angular displacement $\theta$, then the maximum kinetic energy of the bob of mass m is

• A. $\frac{1}{2}m\left(L/g\right)$
• B. $mgL(1-\cos \theta )$
• C. $\left(mgL\sin \theta \right)/2$
• D. $mg/2L$

Answer 1

The correct option is B $mgL(1-\cos \theta )$

Maximum Kinetic energy= Work done.
Now, Work done=$mgh=mg(L-Lcos\theta )=mgL(1-cos\theta )$
Option B is thus correct.