Answer:
75 m /s
Step-by-step explanation:
Acceleration of ball a = change in velocity / time
=( 90 - 60)/ 3 = 10 m s⁻²
Initial velocity u = 60 m/s
a = 10 m s⁻²
time t = 3
distance traveled s = ut + 1/2 at²
= 60 x 3 + .5 x 10 x 3 x 3
= 225 m
Average velocity = total distance traveled /time
= 225 / 3 = 75 m/s