Originally Posted by

**gracey** A train of mass 200,000kg makes a journey on a straight track.

First stage – the train moves with constant acceleration starting at rest and reaching speed of 25ms when it has travelled 0.25km.

Second stage – the train travels 11.25km at a constant speed of 25ms

Third stage – the train has constant deceleration and comes to rest in 40s.

Find the acceleration in the first stage? for this I got 1.25 m/s/s ok

Find the total distance travelled? 0.25 km + 11.25 km + distance of stage 3

distance in meters ... $\displaystyle \textcolor{red}{d = \frac{1}{2}(v_f + v_0)t}$

The resistance to motion is modeled as a constant force of magnitude 100000N throughout each stage of the journey. Find the driving force produced by the train’s engine during the first stage.?

F{net} = ma

let F = train's driving force

F - 100000 = (200,000 kg)/(1.25 m/s/s)