WEBVTT
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in this question, this guy uses lighting down with
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Toby Logan that makes eight degrees sweep the ground acting
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u netminder three forces the weight forced the normal force
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and the frictional force. Given that, how can
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you calculate what is the kinetic coefficient of friction in
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the situation? For that, we have to use
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Newton's second law in a special reference frame, which
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is these one. These will be what I call
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the white direction, and you will be what I
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would call the X direction, then applying Newton's second
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law on the wider action results in the following to
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the Net force on that direction is equal to the
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mass off the guy times acceleration off the guy in
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the direction note that he's not flying away, more
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going blow the Toby Logan show. Acceleration in this
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direction is a question zero, Then the net force
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on the Y direction Is it close to zero?
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But the net force in that direction is composed by
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true forces. One is the normal force, which
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is pointing to the positive direction off the Y axis
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, and the other one is the Y component off
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the way force, which he's these one. So
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this is the Y component off the weight force and
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it's pointing the negative direction off the Y axis.
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So and my nose nowhere. You Why? Easy
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question. Zero. Finally, the normal force is
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he goes to the y component off the weight force
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. Okay. Now applying the same equations of applying
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Newton's second law to the X axis results in the
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following the Net force on that access is he goes
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to the mass off the guy times his acceleration in
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this direction. His is lighting with a constant velocity
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. So that separation in his direction is it close
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to zero then and that forced next interaction is close
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to zero. But the Net force next direction is
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composed by true forces, the frictional force which points
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to the negative direction off the X axis and the
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axe component off the weight force which is point which
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points to the positive direction off the X axis.
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So these things w x then w x my news
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defection or force is equal to zero. Therefore,
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the frictional force is the course w x. But
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now what do we do with that? Remember that
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different channel force is given by the kinetic frictional coefficient
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times the normal force shoot the kinetically from play fusions
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times The normal force is the course to W.
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X. But we want to calculate what is the
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frictional coefficient. And the frictional coefficient can be given
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by the X component off the weight forced, divided
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by the normal force. But as we had seen
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before, the normal force is equals to the Y
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component off the weight force. Then UK is the
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course to w X divided by the way. Why
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, then, we have to use these rectangle.
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Try and go here to finish over. In this
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question, this triangle looks like this. So we
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have here the high party news one off the sites
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on the other side and this is a 90 degree
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angle. Then this is the full weight force disease
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, though where you acts on the easiest w white
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. Now what is this angle and this angle to
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? We can use this under rectum. Who triangle
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here, whose fault? It These clients triangle.
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These is the 90 degree angle before these other angle
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has 82 degrees, meaning that this angle inside the
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triangle must have eight degrees. So this is an
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80 degree angle, and this other one is an
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80 degree angle. Now what do we do with
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that? Well knows that the tangent off this eight
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degree angle is given by the opposite side off the
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triangle W X provided by the address inside off the
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triangle W Y. Then the kinetic frictional coefficient is
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given by the time gent off this eight degree angle
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, and these results in a frictional coefficient off approximately
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0.1 for one, and he is the answer to
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these questions.