A train weighing 100 metric ton is running on a level track with a uniform speed of 72 km/h.If the frictional resistance amounts 0.5 kg per metric ton,find the power of the engine.

Mass of the train is,

m = 10⁵ kg

Uniform speed of the train is, u = 72 km/h = 20 m/s

Frictional force per metric ton is = 0.5 × 9.8 N = 4.9 N

Therefore, frictional force on the train = 4.9 × 100 = 490 N

Since, the train has to overcome this frictional force to maintain a constant speed, the power is given by,

Power = (force)(speed) = 490 × 20 = 9800 W