A ball of mass m , initially at rest, is dropped from a height of 5 meters. If the coefficient of restitution is 0.9, the speed of the ball just before it hits the floor the second time is approximately (take g = 9.8 m/s2 )
1
9.80 m/s
2
9.10 m/s
3
8.91 m/s
4
7.02 m/s