A ball is dropped from a certain height to fall under gravity. After 1 sec another ball is dropped from the same point. What is the distance between them after 3 s from the dropping of second ball?

Options

A. 35 m
B. 25 m
C. 50 m
D. none

Answer

A

Explanation

When the second ball has travelled for a time of 3s, the first ball has travelled for 4s.
`therefore S_1 = 1/2 xx 10 xx 4^2 = 5 xx 16 = 80`
`S_2 = 1/2 xx 10 xx 3^2 = 5 xx 9 = 45 `
`S_1 - S_2 = 35`