Two balls are dropped from same height at 1 second interval of time. The seperation between the two balls after 3 second of the drop of the 1st ball is

Options

(a) 50 m
(b) 40 m
(c) 35 m
(d) 25 m

Correct Answer:

25 m

Explanation:

For the motion of ball is, u=0, a=g, t = 3s.
Using the kinematic equation S=ut+1/2 at².
Let S₁ is the distance covered by the first ball in 3 sec.
.·. S₁=0+1/2x10x(3)²=45 m
Let S₂ is the distance covered by the second ball is 2 sec.
.·. S₂=0+1/2x10x(2)²=20 m
Separation between the two ball is = S₁-S₂
= 45-20 = 25 m .