Momentum & Pulleys Homework: Solving for Velocity

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Momentum conservation is applied to a system involving a pulley, strings, and masses, but the initial calculations yield incorrect results due to neglecting velocity loss during collisions. The proposed solution involves using impulse, where the change in momentum is calculated over the collision time, dt, and the force, F, acting on the bodies. It's emphasized that this impulse method is a general approach and should not be applied without considering the specific forces involved in the scenario. The discussion highlights the importance of accurately accounting for all forces to determine the final velocity. Proper analysis of the collision dynamics is crucial for solving the problem correctly.
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Homework Statement


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The Attempt at a Solution



Taking the pulley and strings, pan, ball, block as system ... momentum is conserved

therefore in Y direction(vertical) ...

-mv = -2mV + mV
-mv = -mV
v = V

which is incorrect (as i expected as there has to be some loss of velocity of particle in a collision)

How should i do it?
 

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Try doing this using impulse:
Let the time of collision be dt and force be F.
Use F.dt = change in momentum for all the 3 bodies, then find the final velocity.
 
ashishsinghal said:
Try doing this using impulse:
Let the time of collision be dt and force be F.
Use F.dt = change in momentum for all the 3 bodies, then find the final velocity.

WARNING: This method by me is a general method of solving collision questions. This is not to be used blindly in this case. Consider the forces which brings the change in momentum.
 
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