Question

Starting from rest, a body travels $36m$ in the first $2$ s of its journey. The distance it can travel in the ${11}^{th}$ second is :

• A. $72$ m
• B. $108$ m
• C. $144$ m
• D. $189$ m

Answer 1

Answer: (D)

$189$ m

$S=1/2\times a\times t^2$
$36=1/2\times a\times 2^2\Rightarrow a=18$ $m{s}^{-2}$
Now Distance travelled in 11th second is Distance travelled in 11s$-$Distance travelled in 10s
$=1/2\times 18\times ({11}^2-{10}^2)$
$=21\times 9=189m$