Question

1. A 10000 kg engine pulls a train of 6 wagons, each of 1500 kg along a horizontal track. If the engine exerts a force of 60000 N and the track offers a friction force of 5000 N, then calculate i. The net acceleration force ii. The acceleration of the train and

Answer 1

Answer :-

Given parameters :-

• Mass of the engine (M) = 10000 kg
• Number of wagons = 6
• Mass of the wagons (m) = 1500 kg
• Force exerted by the engine (F ) = 60000 N
• Frictional force offered by the track (Ff) = 5000 N

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(a) Net force (Fa) = F – Ff

➨ Fa = 60000 N – 5000 N

➨ Fa = 55000 N

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(b) Let us consider the acceleration of the train to be a m/s2

Acceleration is the ratio of net acceleration force by mass, i.e.

★ a = Fa/m

Where m is the mass of the train, it can be calculated as follows

The total mass of the train (m) = Mass of the engine + (Mass of the wagons  × Number of wagons)

➨ m = 10000 + (6 × 1500)

➨ m = 19000 kg

Acceleration of the train (a) = 55000/19000

➨ a = 2.89m/s2

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(c) F21 = m4w × a

F21 = Force applied on Wagon 2 by Wagon 1

• m4w = mass of 4 wagons
• a = acceleration of the train

The force of wagon 1 on wagon 2 = Force of wagon 2 on wagon 1

➨ (4 × 1500 × 2.89 )

➨ 17,340N

∴ The force of wagon - 1 on the wagon - 2 is 17,340 N.

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