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 track offers a friction force of 5000 N, then calculate<

(a) the net acceleration force
(b) the acceleration of train and
(c) the force of wagon 1 on wagon 2 

Answer 1

Mass of the engine = 8000 kg 
Mass of each wagon = 2000 kg, 
Np. of wagons = 5 
Total mass of train = 8000+2000×5= 18000 kg 
Force, F = 40000 N 
Track resistance , R = 5000 N 
Total accelerating force = F −R =40000−5000=35000 N 
Let acceleration = x m/s² 
Acceleration , = Accelerating force / mass 
x=35000/18000= 35/18=1.94 m/s² 
Frictional resistance of 4 wagons = 5000×(2000×4)/18000 =2222 .22 N 
Accelerating force on 4 wagons =2000×4×1.944 =15552 N 
Hence total force exertred by wagon on wagon 2= Accelerating force +Frictional resistance 
=2222 .22 +15552=17774.22 N 
Total force required to produce acc

Answer 2

Explanation:

(a) Net force exerted = 40000 - 5000N

= 35000 N

Total Weight = 8000 + (5× 2000)

= 18000kg

(b) Acceleration = 35000 /18000

= 1.944 ms^-2

Hence, (a)Net Acceleration force = 35000N

and (b)Acceleration of the Train =

1.944ms^-2.