A man weighing 60 kg is a lift moving down with an acceleration of 1.8 m `s^(-2)` . The force exerted by the floor on him is

Options

A. 588 N
B. 480 N
C. zero
D. 696 N

Answer

B

Explanation

Here,
Mass of the man, m = 60 kg
Acceleration of the lifet , `a = 1.8 ms^(-2)`
As the lift moving down with acceleration a, the force exerted by the floor on the man is
N = mg - ma = m (g-a)
`=(60kg) (9.8ms^(-2) -1.8ms^(-2))`
`=(60kg) (8.0 ms^(-2)) = 480N`