PHY 201
Your 'cq_1_07.1' 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 falls freely from rest at a height of 2 meters. Observations indicate that the ball reaches the ground in .64 seconds.
• Based on this information what is its acceleration?
answer/question/discussion: ->->->->->->->->->->->-> :
You have given me the displacement, change in position, and the initial velocity, and the question is to find the acceleration. First, you can find the average velocity, by dividing the change in position by the change in time: 2 m / .64 s = 3.215 meters/second. Then if you know the average velocity and the initial velocity, which is 0 m/s then you can get the final velocity by just multiplying the average velocity by two: 3.125 m/s * 2 = 6.25 m/s. Then you can find the change in velocity, which is difference between the initial and final velocities: 6.25 m/s – 0 m/s = 6.25 m/s. Finally if you know the change in velocity and the time interval you can get the acceleration by just dividing the two into each other: 6.25 m/s / .64 s = 9.77 m/s^2.
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• Is this consistent with an observation which concludes that a ball dropped from a height of 5 meters reaches the ground in 1.05 seconds?
answer/question/discussion: ->->->->->->->->->->->-> :
You are given the displacement, initial velocity, and time interval, then you can find the acceleration. First you find the average velocity: 5 m / 1.05 s = 4.76 m/s. Then, you can find the final velocity with the average velocity and the initial velocity by: 4.76 m/s * 2 = 9.52 m/s. Next, you subtract the difference between the two velocities and you get the change in velocity: 9.52 m/s – 0 m/s = 9.52 m/s. Finally, you use the change in velocity and the change in time to obtain the acceleration: 9.52 m/s / 1.05 s = 9.07 m/s^2. So, this acceleration is not consistent with the acceleration I got in the first question.
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• Are these observations consistent with the accepted value of the acceleration of gravity, which is 9.8 m / s^2?
answer/question/discussion: ->->->->->->->->->->->-> :
The first one is consistent with the accepted value of the acceleration of gravity, but the second falls short about a meter.
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45 minutes
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June 21 around 6:00 pm
&#Your work looks very good. Let me know if you have any questions. &#