Question

A man, of mass $60kg$, is riding in a lift. The weights of the man,when the lift is accelerating upwards amd downwards at $2m/s^2$ are respectively:-
(Taking $g=2m/s^2$)

• A. $720N$ and $480N$
• B. $480N$ and $720N$
• C. $600N$ and $600N$
• D. noneof these

Answer 1

The correct option is A $720N$ and $480N$

Given,

$m=60kg$

$a=2m/s^2$

$g=10m/s^2$

When lift is accelerating upward, then the apparent weight of the man in lift is

$R=m(g+a)$

$R=60(10+2)=720N$

When lift is accelerating downward, then the apparent weight of the man in the lift is,

$R=m(g-a)$

$R=60(10-2)=480N$

The correct option is A.