Question

8. A ball is dropped from a height 2.50 m above the
floor. (a) Find the speed v with which it reaches the
floor. (b) The ball now rebounds. The speed of the
ball is decreased to 30 / 4 due to this collision. How
high will the ball rise?​

Answer 1

the Ball is dropped from

h=2.5m

initial velocity (u)=0

acc due to gravity = - 9.8m/s²

(a)

As per the formula,

v²=u² +2as

v² =0 - 2 ×9.8×2.5

v²= -49

v= 7 m/s

(b)The speed of the

The speed of theball is decreased to 3v / 4 due to this collision.

u '= 3×7/4=5.25m/s

v=0(at the highest point final velocity is always 0)

v² =u² +2ah

0 =u² -2 g h

u²=2 gh

h=5.25×5.25/2×9.8

h=27.56/19.6

h=1.4m