I'm not sure why I'm not getting this problem right. It seems pretty simple to me, but I guess there might be a trick to it?(adsbygoogle = window.adsbygoogle || []).push({});

Suppose that a 50kg block slides along a horizontal surface where the coefficient of kinetic friction between the block and the surface is uk = 0.60. A force F = 400 N is now applied as shown in the drawing, where the angle of the force above horizontal is 20°.

What is the magnitude of the acceleration of the block?

Isn't the equation just 400N*Cos(20)-(9.81 m/s^2)(50kg)(.60) = (50kg)(a)

I get a = 1.63 m/s^2

The choices the online homework gives are

.54, 2.31, 3.27 (2x the accel i get), 6.78, and 8.11

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# Homework Help: Force problem

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