36. What will be the ratio of the distances moved by a freely falling body from rest in 4th and 5th seconds of journey?

36. What will be the ratio of the distances moved by a freely falling body from rest in 4th and 5th seconds of journey?

(a) 4 : 5

(b) 7 : 9

(c) 16 : 25

(d) 1 : 1

Answer :  (b) 7 : 9

For a freely falling body from rest, the distance travelled in the \(n^{th}\) second follows the law of odd numbers.

Distances in successive seconds are proportional to:

\(1 : 3 : 5 : 7 : 9 : \dots\)

Thus,

4th second \(= 7\)

5th second \(= 9\)

Therefore, the ratio of distances is

\(7 : 9\)