In the 200meter race
micheal accelerates at
1.5 seconds. find out
the time taken that
micheal increased his
velocity from 2 meters/s to
9 meters/s.

-Average acceleration is (v2-v1)/(t2-t1).  And we are told that he has constant acceleration of 1.5.  Since acceleration is constant, constant=average.  So:

a=(v2-v1)/(t2-t1) which in this case is:

(9-2)/t=1.5

7=1.5t

t=14/3 seconds

t= 4 2/3 seconds