The normal reaction on a body placed in a lift moving up with constant acceleration 2ms- 2 is 120N . Mass of the body is (Take g=10 ms- 2 )

Question

The normal reaction on a body placed in a lift moving up with constant acceleration 2ms- 2 is 120N . Mass of the body is (Take g=10 ms- 2 ) (A) 10kg (B) 15kg (C) 12kg (D) 5kg

Tardigrade Admin · Accepted Answer

From force diagram shown in figure, <img class="img-fluid question-image" alt="Solution" src="https://cdn.tardigrade.in/q/nta/p-hefe8xm1yxuyvmmg.jpg" /> N-mg=ma0 or 120-mg=2m ∴ m=(120/g + 2)=(120/10 + 2) =10 kg

Q. The normal reaction on a body placed in a lift moving up with constant acceleration $2 m s^{- 2}$ is $120 N$ . Mass of the body is (Take $g = 10 m s^{- 2}$ )

$10 k g$

$15 k g$

$12 k g$

$5 k g$

From force diagram shown in figure,

$N - m g = m a_{0}$
or $120 - m g = 2 m$
$∴ m = \frac{120}{g + 2} = \frac{120}{10 + 2}$
$= 10$ kg

Q. The normal reaction on a body placed in a lift moving up with constant acceleration 2ms−2 is 120N . Mass of the body is (Take g=10ms−2 )

10kg

15kg

12kg

5kg