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I have this problem:

A 4.0 kg block is given an initial speed of 8.0 m/s at the bottom of a 20° incline. The frictional force that retards its motion is 15.0 N. (a) If the block is directed up the incline, how far does it move before stopping? (b)Will it slide back down the incline?

I've managed to get part (a) which was 4.51m but I'm not sure how to start part (b)..

The coefficient of Kinetic Friction was 0.407

Any ideas?

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closed as too localized by dmckee♦ Mar 4 at 1:04

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1 Answer

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Some potentially useful hints/questions:

  1. When the ball gets to the top of its trajectory, it is no longer moving.

  2. Draw a free body diagram for when the ball is at the top.

  3. Under what condition on the forces will it move back down after stopping at the top?

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