Question

a bicyclist is going 200m/s. after 10 seconds the bicyclist is going 150m/s. what is his acceleration

Answer 1

Acceleration:  rate of change of velocity with time.

Here, that acceleration is:

100 m/s - 150 m/s

----------------------------

     10 sec

= (-150 m/s) / (10 sec) = - 15 meters per second squared