Question

A ball moving at 3.0 m/s accelerates in a straight line to 21 m/s in a time of 9.0 seconds. The acceleration of the ball was ____________.

Answer 1

Answer: 2m/s2

Explanation:simple kinematics

vo=3m/s , vf=21m/s ,,,t= 9s

we know that vf=vo+at so a = (vf-vo)/t = (21-3)/9 =2m/s2