Question

A block is kept on the floor of an elevator at rest. The elevator starts descending with an acceleration of 12 m/s² . Find the displacement of the block during the first 0.2 s after the start. Take g = 10 m/s² . 

(A) 10 cm 

(B) 20 cm 

(C) 30 cm 

(D) 40 cm

Answer 1

Correct option is (B) 20 cm

Here acceleration of the lift is 12 m/s2 which is greater than ‘g’.

The body will undergo a free fall condition. Actually the body loses the contact with the floor of the lift.

Answer 2

Correct option is (B) 20 cm