A block of mass m is suspended by a light thread from an elevator. The elevator is accelerating upward with uniform acceleration ‘a’. Find the work done during the first ‘t’ seconds by the tension in the thread.

Open in App

Solution

tension in the thread $= m g + m a$ → [ Psuedo force]

$t e n s i o n = m (g + a)$

now, we have to find displacement of elevator.

use formula, $S = u t + \frac{1}{2} A t^{2}$

here A is net acceleration acts on elevator.

here $u = 0, A = a$ [ upward direction]

so, $S = 0 + \frac{1}{2} a t^{2}$

hence, displacement is $\frac{1}{2} a t^{2}$

now, workdone = Tension × displacement

$= m (g + a) \times \frac{1}{2} a t^{2}$

$= \frac{1}{2} m (g + a) a t^{2} J o u l e$

Suggest Corrections

Similar questions

Q. A block of mass

m

is suspended by a light thread from an elevator. The elevator is accelerating upward with uniform acceleration

a

. The work done during

t

secs by the tension in the thread is:

Q. A block of mass m is suspended by a light thread from an elevator.The elevator is accelerating upward with uniform acceleration a. The work done by tension on the block during t seconds is (1 = 0) :

An elevator starts from rest with a constant upward acceleration. It moves 2 m in the first 0.6 s. A passenger in the elevator is holding a 3 kg package by a vertical string. The tension in the string during acceleration is (Take $g = 9.8 m / s^{2}$ )