Question

A bicycle is going 7 m/s. He squeezes the brakes, giving him an acceleration of -1.2 m/s2. How fast is the bicyclist going after 3 seconds of applying the brakes?

Answer 1

The change in speed is
  (-1.2 m/s²)*(3 s) = -3.6 m/s

So, the speed after 3 seconds is
  7 m/s -3.6 m/s = 3.4 m/s