A `8000kg` engine pulls a train of `5 wagons`, each of `2000kg`, along a horizontal track. If the engine exerts a force of `40000N` and the track offers a frictional force of `5000N`, then calculate:
(a) the net accelerating force, (b) the acceleration of the train, and
(c ) the force of wagon 1 on wagon 2.

Explanation

Mass of `5 wagons= 5xx2000kg = 1000kg,` Total mass, `m= 8000+10000= 18000kg`.
Force exerted = `40000N`
Frictional force `= 5000N`
(a) Net accelerating force, `f= 40000-5000= 35000N` (b) Acceleration of train, `a=f/m = (35000)/(18000)= 1.94 m//s^(2)`
(c) Force of wagon 1 on 2= mass of 4 wagons (behind wagon 1) `xxa=4xx2000xx1.94= 15520N`