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Homework Statement
A child rolls a 0.600-kg basketball up a long ramp. The basketball can be considered a thin-walled, hollow sphere. When the child releases the basketball at the bottom of the ramp. it has a speed of 8.0 m/s. When the ball returns to her after rolling up the
ramp and then rolling back down, it has a speed of 4.0 m/s. Assume the work done by friction on the basketball is the same when the ball moves up or down the ramp and that the basketball rolls without slipping. Find the maximum vertical height increase
of the ball as it rolls up the ramp.
Homework Equations
K1 + U1 + Wf = K2 + U2
The Attempt at a Solution
1)(If i consider the work done static friction force is zero)
From base of the hill to the uphill:
K1= 5/6 MV2, U1=0
k2=0, U2=Mgh and Wf=0
Then 32 = Mgh
h=5.4m...
2)If work done by static friction force is considered then,
From base of the hill to the uphill:
K1= 5/6 MV2, U1=0
k2=0, U2=Mgh and Wf
32+wf = mgh ... 1
from uphill to base of the hill:
Mgh + wf = 8...2
If i solve the equations 1 and 2 then i will get h =3.4m as given in the textbook.
My doubt is, The ball is rolling both up and down the hill due to static friction force. So the workdone by a static friction force is zero. Is this correct??Kindly explain me...
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