Question

A bicyclist is travelling at 25 m/s when he begins to decelerate at -4m/s2 . How fast is travelling after 5 seconds

Answer 1

Initial velocity (Vi) = 25 m/s

acceleration (a) = $-4 m/s^{2}$

time interval (t) = 5 sec

let us assume that final velocity after 5 sec be Vf

As acceleration is constant, we can apply the the equation of motion with constant acceleration i.e. $V_{f} = V_{i} + at$

Hence, $V_{f} = 25 +(-4)(5) = 25 -20 = 5 m/s$

so, the velocity of bicyclist will be 5 m/s after 5 sec