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

The correct option is A 9/25

Distance covered in $5^{th}$, second,

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

and distance covered in 5 second,

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

$\therefore \frac{S_{5^{th}}}{s_5}=\frac{9}{25}$