A lift is moving down with acceleration a. A man in the lift drops a ball inside the lift.The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground are respectively

Options

(a) g,g
(b) g-a,g-a
(c) g-a,g
(d) a,g

Correct Answer:

g-a,g

Explanation:

Acceleration of man in lift a(man) = a
Acceleration of ball ⇒ a(ball) = g
⇒ Relative acceleration
a(rel) = a(base) – a(man) = (g-a)
.·. Acceleration observed by man in lift = g-a
Again for man standing outside a(man) = 0
So, a(relative) = g – 0 = g
.·. Acceleration observed by man standing outside = g