Question

A 8000 kg engine pulls a train of 5 wagons, each of 2000 kg. along a horizontal track. If the engine exerts a force of 40000 N and the track offers a friction force of 5000 N, then calculate:

1. the net accelerating force and
2. the acceleration of the train.

Answer 1

Mass of the rail engine = 8000 kg

Mass of five coaches = 2000 × 5

= 10000 kg

The force exerted by the engine = 40000 N

Friction force = 5000 N

a. Net acceleration force = Force applied by the engine – friction force

= 40000 − 5000

= 35000 N

b. Net force (F) = 35000 N

Total mass = 8000 + 10000

= 18000 kg

F = ma

35000 = 18000 × a

a = `35000/18000`

a = 1.9 m/s ²