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Phy 201
Your 'cq_1_13.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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A ball rolls off the end of an incline with a vertical velocity of 20 cm/s downward, and a horizontal velocity of 80 cm/s. The ball falls freely to the floor 120 cm below.
• For the interval between the end of the ramp and the floor, hat are the ball's initial velocity, displacement and acceleration in the vertical direction?
The initial velocity is 0, the displacement would be at 0 and the acceleration would be 9.8cm/s/s. If we are just looking from the end of the ramp to the floor and not including any information from the incline than this is what I would come up with .
The floor and the ball are at very different levels, so the displacement wouldn't be zero.
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• What therefore are its final velocity, displacement, change in velocity and average velocity in the vertical direction?
The displacement would be 120cm because that the distance the ball has to fall. The change in velocity is 20 cm/s and the average velocity is 10 cm/s.
120 cm is the vertical displacement for this phase. 20 cm/s is not the average velocity for the fall but the vertical velocity. The acceleration of a freely falling object is 980 cm/s^2.
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• What are the ball's acceleration and initial velocity in the horizontal direction, and what is the change in clock time, during this interval?
The balls initial velocity is 0 because it starts at rest. We first can find the ‘dt by vAve= 80/2= 40cm/s, then vAve= ‘ds/’dt, so 40cm/s= 120cm/’dt. ‘dt= 3seconds.
Then we can find the acceleration by: aAve= ‘dv/’dt= aAve= 80cm/3s= 26.7cm/s/s.
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• What therefore are its displacement, final velocity, average velocity and change in velocity in the horizontal direction during this interval?
The displacement is 120cm. The average velocity is 40cm/s and the change in velocity is 80cm/s.
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• After the instant of impact with the floor, can we expect that the ball will be uniformly accelerated?
Yes, we can because the ball has completely stopped.
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• Why does this analysis stop at the instant of impact with the floor?
The ball then stops moving.
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15 minutes
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Solution
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