Question

A force of $10N$ is applied on a object of mass $1kg$ for $2s$, which was initially at rest. What is the work done on the object by the force?

• A. $200J$
• B. $20J$
• C. $16J$
• D. $180J$

Answer 1

The correct option is A $200J$

Force acting on the object $F=10N$

Mass of object $m=1kg$

Acceleration of the object $a=\frac{F}{m}$

$\therefore$ $a=\frac{10}{1}=10m/s^2$

Initial speed of the object $u=0m/s$

Distance covered by it in $2s$, $S=ut+\frac{1}{2}a{t}^2$ where $t=2s$

$\therefore$ $S=0+\frac{1}{2}\times 10\times 2^2=20m$

Work done $W=FS$

$⟹$ $W=10\times 20=200J$