A crate of mass m = 100 kg is pushed at constant speed up the frictionless ramp (theta= 27.0°) by a horizontal force F.(adsbygoogle = window.adsbygoogle || []).push({});

What is the magnitude of the force exerted by the ramp on the crate?

My x-y coordinate system has x+ pointing up the ramp.

I assume that the force in question is the Normal force, which points directly along my positive y-axis.

No acceleration in the y direction (or x direction either, but that's irrelevent for this part of the problem), so

[itex]\Sigma\\F_{y}=N-mg_{y}=N-mg\cos\theta=0[/itex]

which gives [itex]N=mg\cos\theta=(100kg)(9.81m/s^2)(cos27^o)=874N[/itex]

But that's not the right answer... (and I don't know what the right answer is, either)

Help?

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# Homework Help: Normal force on an inclined plane

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