Answer to Question #277840 in Physics for Bebe

Question

A fast train traveling at 22.0 m/s trails behind a slower train traveling at 16.0 m/s. The fast train is 150 m behind that of the slower train when it started to stop. The fast train then started to accelerate at 0.120 m/s², opposing its velocity. Will the trains collide?

Answer 1

The distance required to reach 16 m/s:

$$d=\frac{v_f^2-v_s^2}{2a}=950\text{ m}.$$

And there is just 150 m between them. The collision is unavoidable.