Acyclist is riding along at a constant velocity of 15 m/s. he then accelerates at a uniform rate of 0.50 m/s2 over a distance of 64 m. how long did he accelerate for?

Cyclist will take 4 seconds to travel 64 meter.

Explanation:

 We have equation of motion, , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.

 In this case initial velocity = 15 m/s, acceleration = 0.50 , we need to calculate time when displacement = 64 meter.

 Substituting

 t = 4 seconds or t = -64 seconds(which is not possible).

So he will take 4 seconds to travel 64 meter.