Question

A force acts for $10s$ on a stationary body of mass $100kg$ after which the force ceases to act. The body moves through a distance of $100m$ in the next $5s$. Calculate the velocity acquired by the body and the acceleration produced by the force.

• A. $10$ $m$ $s^{-1}$, $2$ $m$ $s^{-2}$
• B. $2$ $m$ $s^{-1}$, $2$ $m$ $s^{-2}$
• C. $20$ $m$ $s^{-1}$, $4$ $m$ $s^{-2}$
• D. $20$ $m$ $s^{-1}$, $2$ $m$ $s^{-2}$

Answer 1

Answer: (D)

$20$ $m$ $s^{-1}$, $2$ $m$ $s^{-2}$

Mass, $m=100kg$
Time interval, $\Delta t=10s$
(i) Distance traveled in next 5 seconds, $d=100m$
Thus, velocity acquired by body, $v=\frac{d}{t}=\frac{100}{5}=20m/s$
(ii)Acceleration produced by the force, $a=\frac{v}{\Delta t}=\frac{20}{10}=2m/s^2$
(iii) Magnitude of force, $F=ma=100kg\ast 2m/s^2=200N$