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View Full Version : The Work - Energy Theorem in a pulley?


erik-the-red
Sep24-05, 04:00 PM
Consider the system shown in the figure. The rope and pulley have negligible mass, and the pulley is frictionless. The coefficient of kinetic friction between the 8.00-kg block and the tabletop is \mu_k=0.250. The blocks are released from rest.

Use energy methods to calculate the speed of the 6.00-kg block after it has descended 1.50 m.

\Delta * K = (1/2)(m)(v_f^2 - v_i^2)

But, it was at rest, so (1/2)(m)(v_f^2) is what matters.

What do I do next?

Fermat
Sep24-05, 05:19 PM
You will have a loss in PE balanced by a gain in KE and work done.

What is it that loses PE, and by how much ?

What are the gains in KE and by how much ?

What work is done and how much ?