A pendulum is executing simple harmonic motion and its maximum kinetic energy is `K_(1)`. If the length of the pendulum is doubled and it perfoms simple harmonuc motion with the same amplitude as in the first case, its maximum kinetic energy is `K_(2)` Then:

Options

A. `k_(2)=2k_(1)`
B. `k_(2)=k_(1)`
C. `k_(2)=k_(1)/4`
D. `k_(2)=k_(1)/4`

Answer

D

Explanation

`KE_(max)=1/2momega^(2)A^(2)`
or `(k_(1))/(k_(2))= (g//l)/(g//2l) or k_(2)=k_(1)/2`