Question

The normal reaction on a body placed in a lift moving up with constant acceleration $2 \, m \, s^{- 1}$ is $120 \, N$ . Mass of the body is (Take $g=10 \, m \, s^{- 2}$ )

• A. $10kg$
• B. $15kg$
• C. $12kg$
• D. $5kg$

Answer 1

Answer: (A)

$10kg$

Answer 2

From force diagram shown in figure, $N-mg=ma_{0}$ or $120-mg=2m$ $\therefore m=\frac{120}{g + 2}=\frac{120}{10 + 2}$ $=10$ kg