Question

A body `A` starts from rest with an acceleration `a_1`. After `2` seconds, another body `B` starts from rest with an acceleration `a_2`. If they travel equal distances in the `5th` second, after the start of `A`, then the ratio `a_1 : a_2` is equal to :
A. `5 : 9`
B. `5 : 7`
C. `9 : 5`
D. `9 : 7`

Answer 1

Correct Answer - A
According to problem
Distance travelled by body `A` in `5^(th) sec` and distance travelled by body `B` in `3^(rd) sec` of its motion are equal.
`0 + (a_1)/(2)(2 xx 5 - 1) = 0 + (a_2)/(2)[2 xx 3 - 1]`
`9 a_1 = 5 a_2 rArr (a_1)/(a_2) = (5)/(9)`.