What Went Wrong in My Incline Friction Problem?

AI Thread Summary
The discussion focuses on a physics problem involving incline friction, where the original poster struggles to identify an error in their solution. Key feedback indicates a misunderstanding regarding the force of the rope, which was incorrectly assumed to equal the weight of the hanging mass. Instead, the correct approach involves defining the rope tension as T and applying Newton's second law to both masses. By combining the resulting equations, one can accurately solve for the acceleration. This clarification is essential for resolving the problem effectively.
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Hello, this is a physics problem I worked out an cannot determine what I did wrong.
Attached is the problem and my solution. Any help would be very appreciated.
Thanks.

Homework Statement


Attached

Homework Equations



F = ma, f_k = Mu_k * N, dx = v0t + 1/2at^2

The Attempt at a Solution


Attached
 

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Looks to me that you assumed the force of the rope on the mass was equal to the weight of the hanging mass. That's not true. (If it were true, the hanging mass would be in equilibrium.)

Instead, call the rope tension T. Apply Newton's 2nd law to both masses, then combine the equations to solve for the acceleration.
 
Ooooh yeah. Thanks!
 
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