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. $\frac{9}{25}$
• B. $\frac{3}{5}$
• C. $\frac{25}{9}$
• D. $\frac{1}{25}$

Answer 1

The correct option is A $\frac{9}{25}$

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,

$S_5=ut+\frac{1}{2}a{t}^2=0+\frac{1}{2}\times a\times 25=\frac{25a}{2}$

$\therefore \frac{S_{5^{th}}}{S_5}=\frac{9}{25}$