A bob of pendulum of mass 50 g is suspended by a string with the roof of an elevator. If the lift is falling with a uniform acceleration of 5 m s- 2, the tension in the string is (g = 10 m s- 2)

Question

A bob of pendulum of mass 50 g is suspended by a string with the roof of an elevator. If the lift is falling with a uniform acceleration of 5 m s- 2, the tension in the string is (g = 10 m s- 2) (A) 0.5 N (B) 0.225 N (C) 0.25 N (D) 0.025 N

Tardigrade Admin · Accepted Answer

Here, mass of bob, m=50 g =0.05 kg Since, the lift is falling downward with a uniform acceleration of 5ms- 2 , hence tension in the string, T=m(g - a) =0.05(10 - 5) =0.05× 5 =0.25 N

Q. A bob of pendulum of mass $50 g$ is suspended by a string with the roof of an elevator. If the lift is falling with a uniform acceleration of $5 m s^{- 2},$ the tension in the string is $(g = 10 m s^{- 2})$

$0.5 N$

$0.225 N$

$0.25 N$

$0.025 N$

Here, mass of bob, $m = 50 g$
$= 0.05 k g$
Since, the lift is falling downward with a uniform acceleration of $5 m s^{- 2}$ , hence tension in the string,
$T = m (g - a)$
$= 0.05 (10 - 5)$
$= 0.05 \times 5$
$= 0.25 N$

Q. A bob of pendulum of mass 50g is suspended by a string with the roof of an elevator. If the lift is falling with a uniform acceleration of 5ms−2, the tension in the string is (g=10ms−2)

0.5N

0.225N

0.25N

0.025N