How Is Total Work Calculated for Two Connected Blocks with Friction?

AI Thread Summary
Total work for the 20 N block is calculated using the formula w = f · d, where f is the net force and d is the distance moved. The kinetic friction force is determined by f_k = μ_k · n, leading to a calculation of work done against friction. The user initially miscalculated the work as 0.75 J but later resolved the problem independently. Frustration was expressed over the lack of timely responses from the forum. The discussion highlights the importance of understanding friction in work calculations for connected blocks.
james brug
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Homework Statement



Two blocks are connected by a very light string passing over a massless and frictionless pulley . The 20.0 N block moves 75.0 cm to the right and the 12.0 N block moves 75.0 cm downward.

Find the total work done on the 20 N block if \mu _s\;=(coeff. of static friction)=0.500 and \mu _k \;\;\;\;=(coeff. of kinetic friction)=0.325 between the table and the 20 N block.

Homework Equations


w=f\cdot d
f_k=\mu_k\cdot n
f_s\leq\mu_s\cdot n

The Attempt at a Solution


w=[7.5N-(.325)(20N)](.75m)=.75J--wrong.
 
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Never mind. I've solved it myself through some careful research and considerable effort. It is unfortunate that no one was able to answer this in time. Perhaps you people want some monetary compensation? Or maybe no one liked my problem. Not particularly hard, is it?
 

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