Moving train - kinematics problem

[silvercats]

Homework Statement

A 12 metrick ton train is moving with a 72KMH velocity.when brakes It comes to rest in 2 mins.find the force caused by the force?

Homework Equations

F=ma
a=v/t

The Attempt at a Solution

didn't get the correct answer which is given on the answers page(only the answer not the steps)

 

[Lok]

The steps are:

1) Transform everything in kg, m/s, s.
2) Find deceleration of train with equation 2 (assuming it is constant)
3) hopefully equation 1 will be all that is needed as your final question could use some work.

 

[silvercats]

thank you...