Question

A block of mass $2$ $kg$ is placed on a smooth horizontal surface. Two forces $F_1=20$ $N$ and $F_2=5$ $N$ start acting on the block in opposite directions as shown. If blocks gets displaced by $5$ $m$ in the direction of net force then work done by $F_2$ is:

• A. $-75$ $J$
• B. $75$ $J$
• C. $-25$ $J$
• D. $25$ $J$

Answer 1

The correct option is C $-25$ $J$

The block gets displaced in direction of $F_1$
$\therefore$ Workdone by $F_2=F_2\cdot x=5\times 5\cos {180}^o=-25$ $J$