Question

A force applied by an engine of a train of mass $2.05\times {10}^{6}kg$ changes its velocity from 5 m/s to 25 m/s in 5 minutes. The power of the engine is

• A. 1.025 MW
• B. 2.05 MW
• C. 5MW
• D. 5 MW

Answer 1

The correct option is B

2.05 MW

$Power=\frac{Workdone}{time}=\frac{Increaseinkineticenergy}{time}=\frac{\frac{1}{2}m(v_2^2-v_1^2)}{t}=\frac{\frac{1}{2}\times 2.05\times {10}^6\times [{25}^2-5^2]}{5\times 60}$

$=2.05\times {10}^{6}watt=2.05MW$