A person of $60 \mathrm{~kg}$ mass is in a lift which is coming down such that the man exerts a force of…
A person of $60 \mathrm{~kg}$ mass is in a lift which is coming down such that the man exerts a force of $150 \mathrm{~N}$ on the floor of the lift. Then the acceleration of the lift is $\left(g=10 \mathrm{~ms}^{-2}\right)$
$7.5 \mathrm{~ms}^{-2}$
$40.0 \mathrm{~ms}^{-2}$
$22.5 \mathrm{~ms}^{-2}$
$15.0 \mathrm{~ms}^{-2}$
Solution
Here $g_{e f f}=g-a$
So, $m(g-a)=150 \mathrm{~N}$
$60(10-a)=150$
$a=7.5 \mathrm{~m} / \mathrm{s}^2$