A block with mass 10.0 kg is placed on an inclined plane with slope angle(adsbygoogle = window.adsbygoogle || []).push({}); 30degrees and is connected to a second hanging block that has massmby a cord passing over a small, frictionless pulley. The coefficient of static friction is 0.45, and the coefficient of kinetic friction is 0.35.

(a)Find the massmfor which the 10.0 kg block moves up the plane at a constant speed once it has been set in motion.

(b)Find the massmfor which it moves down the plane at constant speed once it has been set in motion.

(c)For what range of values ofmwill the block remain at rest if it is released from rest? (Use g = 10 m/s^2)

So the first thing I note is that [tex] \mu_{s} = 0.45 [/tex] and [tex] \mu_{k} = 0.35 [/tex]. I also know that I am dealing with a 30-60-90 right triangle, which will make the problem easier. Now I draw the free body diagram. The force of gravity [tex] w = mg [/tex] is acting on the both blocks. The tension of the rope is acting on both blocks(same for each block). Static friction is acting on the 10.0 kg block, directed in the [tex] - x [/tex] direction.

So for part (a) the key phrase isonce it has been set in motion. That means kinetic friction is important in this case. So I calculate the kinetic friction of the block to be: [tex] f_{k} = (0.35)(100 N) = 35 N [/tex]. What would I do from here?

For part (b), the mass has to be less than the mass of the block from the previous question, because it is moving down the ramp.

For (c) the masses have to be such that they do not break overcome the static friction [tex] f_{s} [/tex].

Any help is appreciated

Thanks

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# Homework Help: Inclined Plane block of mass

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