An 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:

(a) the net accelerating force and

(b) the acceleration of the train

(a) Given,

Force exerted (F) = 40,000 N

Force of friction = -5000 N

Net accelerating force = 40,000 + (-5000) = 35,000 N

Hence, net accelerating force = 35,000 N

(b) Total mass of the train = mass of engine + mass of each wagon = 8000 + (5 × 2000) = 8000 + 10000 = 18000 kg

Now, as Force = mass x acceleration

Substituting we get,

35000 = 18000 x a

a = $\dfrac{35000}{18000}$ = 1.94 ms^-2

Hence, acceleration of the train is 1.94 ms^-2