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All right.
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So here we have a problem on bio -human biomechanics.
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The fastest serve in tennis was done by big bill tilton in 1931, as the problem states.
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That's measured at 73 .14 meters per second.
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We know the mass of tennis ball is 57 grams.
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It's in contact with tennis racket for 30 milliseconds.
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The ball is starting from rest.
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We're assuming a constant acceleration.
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That's going to be our cue to use kinematics.
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And we want to know what forested bill's racket exert on the tennis ball.
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With the assumption that it was all horizontal force.
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Then we're going to do a free body diagram on that for part b.
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So starting off with what we know, we know the velocity original.
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It's zero, right as the ball contacts it and brings it to a stop before accelerating.
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The velocity final given was 73 .14 meters per second.
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Mass is 57 grams.
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Time, we're going to go ahead and convert that to seconds because milliseconds won't be particularly helpful .030 seconds.
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We're looking for the force and we will need acceleration to get there...