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Phy 231
Your 'cq_1_08.1' 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 is tossed upward with an initial velocity of 25 meters / second. Assume that the acceleration of gravity is 10 m/s^2 downward.
• What will be the velocity of the ball after one second?
answer/question/discussion: ->->->->->->->->->->->-> :
vf = v0 + a*`dt
vf = 25m/s - 10m/s^2(1sec)
vf = 15m/s
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• What will be its velocity at the end of two seconds?
answer/question/discussion: ->->->->->->->->->->->-> :
vf = 25m/s - 10m/s^2(2sec)
vf = 5m/s
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• During the first two seconds, what therefore is its average velocity?
answer/question/discussion: ->->->->->->->->->->->-> :
15m/s + 5m/s = 20m/s / 2 = 10m/s
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• How far does it therefore rise in the first two seconds?
answer/question/discussion: ->->->->->->->->->->->-> :
10m/s * 2sec = 20m
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• What will be its velocity at the end of a additional second, and at the end of one more additional second?
answer/question/discussion: ->->->->->->->->->->->-> :
After 3 sec: -5m/s
After 4 sec: -15m/s
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• At what instant does the ball reach its maximum height, and how high has it risen by that instant?
answer/question/discussion: ->->->->->->->->->->->-> :
vf = v0 + a*`dt
0m/s = 25m/s - 10m/s^2 *`dt
10m/s^2*`dt = 25m/s
`dt = 25m/s / 10m/s^2 = 2.5sec
V_avg = 25m/s / 2 = 12.5m/s
Height = 12.5m/s * 2.5sec = 31.25m
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• What is its average velocity for the first four seconds, and how high is it at the end of the fourth second?
answer/question/discussion: ->->->->->->->->->->->-> :
25m/s - 15m/s = 10m/s / 2 = 5m/s
5m/s * 4 sec = 20m
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• How high will it be at the end of the sixth second?
answer/question/discussion: ->->->->->->->->->->->-> :
vf = 25m/s - 10m/s^2*(6sec)
vf = -35m/s
v_avg = 25m/s - 35m/s / 2
v_ avg = -10m/s / 2
-5m/s * 6 sec = -30m
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14 minutes
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&#Very good responses. Let me know if you have questions. &#