Is the conservation of energy being applied correctly in this scenario?

AI Thread Summary
The discussion focuses on applying the conservation of energy principle to a system involving two masses connected by a string over a frictionless pulley. The initial energy equation is set up correctly, equating the gravitational potential energy of the first mass to the sum of the gravitational potential energy of the second mass and the kinetic energy of both masses. The calculations yield a speed of 4.43 m/s for the second mass just as the first mass hits the table. Participants confirm the setup and calculations are correct, with no significant concerns raised about the application of energy conservation in this scenario. The discussion emphasizes the importance of correctly applying energy principles in physics problems.
Kuklinski
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I don't know if I'm setting up the energies correctly.

1. Two objects are connected by a light string passing over a light, frictionless pulley. The object of mass m1=5.00kg is released from rest at a height h=4m above the table. Using the isolated system model, (a) determine the speed of the object of mass m2=3.00kg just as the 5.00-kg object hits the table and (b) find the maximum height above the table which the 3.00-kg object rises.
2. E1=Ef
KE=.5mv2
U=mgh
3. Ei=Ef
m1gh=m2gh + .5(m1+m2)v2
5(9.8)(4) = 3(9.8)(4) + .5(8)(v2
v=4.43m/s
 
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Welcome to PF!

Hi Kuklinski! Welcome to PF! :smile:
Kuklinski said:
Two objects are connected by a light string passing over a light, frictionless pulley. The object of mass m1=5.00kg is released from rest at a height h=4m above the table. Using the isolated system model, (a) determine the speed of the object of mass m2=3.00kg just as the 5.00-kg object hits the table and (b) find the maximum height above the table which the 3.00-kg object rises.

Ei=Ef
m1gh=m2gh + .5(m1+m2)v2
5(9.8)(4) = 3(9.8)(4) + .5(8)(v2
v=4.43m/s

Yes, that looks fine. :smile:

What's worrying you about it? :confused:​
 

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