Question

An engine pulls a train 1 km over a level track. Calculate the work done by the train against friction if frictional force is $5\times {10}^{5}N$.

• A. $5\times {10}^{8}J$
• B. $5\times {10}^{4}J$
• C. $8\times {10}^{8}J$
• D. $6\times {10}^{8}J$

Answer 1

The correct option is A $5\times {10}^{8}J$

Given, frictional force, $F=5\times {10}^{5}N$ ;
Displacement of the train, $s=1km=1000m$
Work done by the train against frictional force,
$W=F\times s=(5\times {10}^5)\times \left(1000\right)=5\times {10}^{8}J$ .