Question

A body of mass $1kg$ is initially at rest. A force of $10N$ is applied on it for $2s$. What is the work done on the object?

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

Answer 1

The correct option is A $200J$

Given,
Force $F$ = $10N$
Mass $m$ = $1kg$
Time $t$ = $2s$
Work done $W=F\times S$, where F is the force and S is the displacement.
Initial velocity $u=0$
We know $F=m\times a$
$10=1\times a$
$a=10m{s}^{-2}$
Substituting the values in equation of motion, $s=ut+\frac{1}{2}a{t}^2$
Or $s=0+\frac{1}{2}a{t}^2$
$=\frac{1}{2}\times 10\times (2{)}^2=20m$
$\therefore W=F\times S=10\times 20=200J$