(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A crate is pushed at constant velocity across a rough, horizontal surface by a push forceP. The crate has a weight of 73N. Coefficient of kinetic friction between the crate and the floor is 0.41. Vector forcePpoints at an angle of 37 degrees below the horizontal. What is the magnitude of the normal force?

2. Relevant equations

f_{k}= μ_{k}N

constant velocity indicatesvand therefore_{0}=v_{final}a=0

no movement in the y direction, thereforeƩF_{y}=0

These are random things that I have found online but I'm not sure if they're true:

Fcosθ=f(The horizontal component of the push force is equivalent to to friction)

3. The attempt at a solution

The problem is, I don't have the magnitude of the push force. I don't know where to go from here, but I have tried many things.

To find the kinetic friction:

f_{k}= μ_{k}N

=(0.41)(73N)

=29.9N

UsingFcosθ=f, I assume that 29.9N is the horizontal component of the push force. I then find the vertical component of the push force:

P_{y}=29.9N*tan37

P_{y}=19.6N

I then add this to the weight to find the Normal Force:

73+19.6=92.6N

The Normal Force is not 92.6N. This problem is from an exam I failed last semester, and I have the correct answer now, but I can't get to it.

Thank you in advance, for anyone who can help me out.

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# Homework Help: Kinetic Friction, Undefined Pushing Force, Find Normal Force.

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