A Block Sliding Down an Incline

AI Thread Summary
The discussion focuses on calculating the work done by gravity and the normal force on a 5 kg block sliding down a 30-degree incline. The work done by gravity is determined to be 61.25 J using the formula Wgravity = mgh, where the height is derived from the incline's angle. There is uncertainty regarding the work done by the normal force, with a question raised about its equivalence to the work done by gravity. Additionally, the presence of friction complicates the analysis, suggesting that the normal force's work is not the same as that of gravity. Clarification on these calculations is sought to resolve the confusion.
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Homework Statement



Starting from rest, a 5 kg block slides 2.5 m down a rough 30 degree incline. The coefficient of kinetic friction between the block and the incline is 0.436. The acceleration of gravity is 9.8 m/s2.

Find the work done by the force of gravity.

Find the work done by the normal force.

Homework Equations



Wgravity = mgh

The Attempt at a Solution



I figured out work done by force of gravity:

Wgravity = (5 kg)(9.8 m/s2)(2.5sin30) = 61.25 J

However, I don't know how to find the work done by the normal force. Is it the same as work done by gravity?
 
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There is another force involved - friction.
 

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