Question

A train moving west with an initial velocity of 20 m/s accelerates at 4 m/s2 for 10 seconds. During this time, the train moves a distance of
meters.

Answer 1

The distance is

$$x=v_0t+\frac{at^2}{2},\\\space\\ x=20\cdot10+\frac{4\cdot10^2}{2}=400\text{ m}.\\\space\\$$