Answer: acceleration of the train = 7 m/s^2
Explanation: We are going to use the formula for acceleration,
acceleration of a moving body is the change in speed per unit of time, hence the formula for finding acceleration is
a = (v-u)/t
here, a = acceleration
v = final speed
u = initial speed
t = total time taken
here (v-u) will give the change in velocity since it's the difference between the final and initial velocity of the train
Given, v = 17 m/s
u = 3 m/s
t = 2 s
∴ a = (17-3)/2
= 14/2
= 7 m/s^2