Question

A man of weight W is standing on a lift which is moving upward with an acceleration a. The apparent weight of the man is

• A. $W(1+\frac{a}{g})$
• B. W
• C. $W(1-\frac{a}{g})$
• D. $W(1-\frac{a^2}{g^2})$

Answer 1

The correct option is A $W(1+\frac{a}{g})$

Apparent weight is the normal reaction provided by the floor of the lift.

Working from the frame of reference of lift, net normal reaction by the floor is pseudo force $ma$ + real weight $mg$.

Apparent weight is $W_a=m(g+a)$

$\Rightarrow$ $W_a=mg(1+\frac{a}{g})=W(1+\frac{a}{g})$ $(\because W=mg)$