Question

A body starting from rest moves with constant acceleration. The ratio of distance covered by the body during the 5th sec to that covered in 5 sec is

• A. 9/25
• B. 3/5
• C. 25/9
• D. 1/25

Answer 1

Answer: (A)

9/25

Answer 2

Distance covered in 5^th second,

$S_{5^{th}} = u + \frac{a}{2}(2n - 1) = 0 + \frac{a}{2}(2 \times 5 - 1) = \frac{9a}{2}$

and distance covered in 5 second,

$S_{5} = ut + \frac{1}{2}at^{2} = 0 + \frac{1}{2} \times a \times 25 = \frac{25a}{2}$

$\therefore$ $\frac{S_{5^{th}}}{S_{5}} = \frac{9}{25}$