Question

6.
A ball is dropped from the roof of a lift. At this
moment the lift is moving downward with an
acceleration 'a' (a <g). The ratio of acceleration of
the ball for an observer inside the lift to the
acceleration of ball for an observer on the ground
will be
(1) ( a):9 (2) 9:(9. a)
(3) lg-a):9 (4) (g-a): (g-a)​

Answer 1

Answer:

3)(g-a):g

Explanation:

Upward force acting on the ball R = ma

Downward force acting on the ball W=mg where g is the acceleration due to gravity.

Apparent weight of the ball W'= W-R

W’= mg - ma = m(g-a)

Hence apparent acceleration = g-a

For the person standing outside, acceleration of the ball = g = 9.8 m/s²