Discussion Forum



1)

A simple pendulum of length 1m  is freely suspended from the ceiling of an elevator. The time period  of small oscillations as the elevator moves up with an acceleration of 2m/s2 is (use g=10 m/s 2)


A) $\frac{\pi}{\sqrt{5}}s$

B) $\sqrt{\frac{2}{5}}\pi s$

C) $\frac{\pi}{\sqrt{2}}s$

D) $\frac{\pi}{\sqrt{3}}s$

Answer:

Option D

Explanation:

 Given,

 Length of simple pendulum (L) =1m

 Acceleration (a) =2 m/s2

 Gravitation  acceleration (g)=10 m/s2

 We know that,

    $T= 2 \pi \sqrt{\frac{l}{g+a}}=2\pi\sqrt{\frac{1}{10+2}}$

$= 2 \pi \sqrt{\frac{1}{12}}=\pi\sqrt{\frac{4}{12}}$

$I= \frac{\pi}{\sqrt{3}}s$