Question

A train consisting of 30 wagons each of 15 tons and is
pulled by an engine of power 90 KW. If the frictional
force and air resistance force offered per ton of the
train is 12 N then the maximum velocity with which
the train can travel is
(1) 40 Kmph (2) 60 Kmph
(3) 80 Kmph (4) 100 Kmph​

Answer 1

Answer:

Option (2) 60 kmph

Explanation:

Total weight of the train = 30 × 15 = 450 tonnes

Resistive force = 450 × 12 = 5400 N

Power of the engine = 90KW = 90000 W

We know that Power

P = F × v

Therefore

v = P/F

  = 90000/5400 m/s

 = 100/6 m/s

 =  (100/6) × (3600/1000) km/h

  = 60 km/h

Hope the answer is helpful.