00:01
So we're going to be covering problem 17 of chapter 5 of the physics fifth book.
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The question starts, a 136 kilogram crate is at rest on the floor.
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A worker attempts to push it across the floor by applying a 412 newton force horizontally.
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Take the coefficient of static friction between the crate and the floor to be 0 .37, and for part a, show the crate does not move.
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For part b, a second worker helps by pulling up on the crate.
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Minimum vertical force must this worker apply so that the crate starts to move across the floor.
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And for part c, if the worker applies a horizontal rather than their vertical force, what minimum force in addition to the 412 newton force must be exerted to get the crate started? so this is a setup we have for the entire question.
00:51
We have our 136 kilogram crate here, and it has some weight mg, which is obviously equal to 136 times by 9 .8.
01:03
And then we have some normal force which we need to calculate and we know our mu is 0 .37 and in part a we just need to calculate we just need to show that this 412 force newton force is not enough to push the crate or to get it started for part b we we have some force the workers pulling up on the crate width which will obviously have some effect on n and we need to work out how hardiest to pull up in order to get the crate moving...