Question

Find the total displacement of a body in $8s$ Starting from rest with an acceleration of $20cm/s^2$.

• A. 64 m
• B. 64 cm
• C. 640 cm
• D. 0.064 m

Answer 1

Answer: (C)

When a body starts from rest its initial velocity is zero.
Using 2nd equation of motion, we have
$s=ut+\frac{1}{2}a{t}^2$
where, $s$ is displacement undergone,
$u$ is initial velocity,
$a$ is acceleration due to gravity and $t$ is time
Since, body starts from rest, so $u=0$
Here, $a=20cm/s^2,t=8s$
$\therefore s=0+\frac{1}{2}\times 20\times 8\times 8=640cm$