Question

A car is being driven at a constant speed of $5m/s$ by a force of $3\times {10}^{8}N$. It takes $2$ minutes to reach its destination. What is the work done?

• A. $15\times {10}^{8}J$
• B. $18\times {10}^{10}J$
• C. $6\times {10}^{10}J$
• D. $10\times {10}^{8}J$

Answer 1

Answer: (B)

$18\times {10}^{10}J$

Given,

Speed, $v=5m/s$

Time taken, $t=2min$

$t=2\times 60=120s$

Force applied, $F=3\times {10}^{8}N$

Displacement, $d$

We know,

$v=\frac{d}{t}$

$⟹d=v\times t$

$d=5\times 120$

$d=600m$

Work done, $W=F\times d$

$W=3\times {10}^8\times 600$

$W=18\times {10}^{10}J$