A body starting from rest moves with const

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

A

$9/25$

B

$3/5$

C

$25/9$

D

$1/25$

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

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,

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

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