Answer:
The velocity at the top is 7.65 m/s
Solution:
As per the question:
Height of the ball, h = 0.760 m
Linear speed of the ball at bottom, v = 8.57 m/s
Let the speed at the top be v' m/s
Now,
Using the principle of the work energy theorem:
The total mechanical energy of the system remain conserved.
[tex]PE + KE = 0[/tex]
where
PE = mgh = potential energy
KE = [tex]\frac{1}{2}m(v'^{2} - v^{2})[/tex] = change in kinetic energy
Thus
[tex]mgh + \frac{1}{2}m(v'^{2} - v^{2})[/tex] = 0[/tex]
[tex]v'^{2} = v^{2} - 2gh[/tex]
[tex]v' = \sqrt{8.57^{2} - 2\times 9.8\times 0.760} = 7.65\ m/s[/tex]