Answer:
a)3.2m/s^2
b) -480,000N
Explanation:
mass of train= 150,000kg
velocity of train=40m/s
acceleration is negative
v^2=u^2-2as
v=0m/s
u=40m/s
s=250m
0=1600-500a
500a=1600
deceleration of 3.2m/s^2
newton's second law
F=ma
F= (150,000× -3.2)
F= -480,000N