Question

A boy of mass 40 kg is standing in a lift,
which is moving downwards with an acceleration 9.8 $m/s^2$. The apparent weight of
the boy is (Take $g=9.8m/s^2$)

• A. $40\times 9.8$ N
• B. Zero
• C. $40/9.8$ N
• D. $40$ N

Answer 1

Answer: (B)

Zero

Given,

mass of boy is $40kg$

Velocity of boy moving downward direction is $9.8m/s^2$

Acceleration due to gravity is $9.8m/s^2$

Then,

By equating force in downward direction and upward direction we will get

$mg=m(g-a)$

Hence,

Apparent weight $=m(9.8-9.8)$

Apparent weight $=0N$

Correct option is $B$ option.