v=√2×g×h=√2×9.8×4.9=9.8m∕s where: g=9.8m∕s2 (acceleration due to gravity) h=4.9m‌ (height) ‌ Next, calculate the velocity after the first bounce using the coefficient of restitution e=‌
3
4
: v‌bounce ‌=e×9.8=‌
3
4
×9.8=7.35m∕s The time taken for the ball to travel up and back down after the first bounce, until it hits the surface again, is: ‌t=‌
2v‌bounce ‌
g
=‌
2×7.35
9.8
‌t=‌
14.7
9.8
=1.5s Therefore, the ball will hit the surface for the second time after 1.5 seconds.