cq_1_081

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PHY 121

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: ->->->->->->->->->->->-> :

 The velocity of the ball will be 15m/s after one second.

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What will be its velocity at the end of two seconds? 

answer/question/discussion: ->->->->->->->->->->->-> :

 After two seconds, the velocity will be 5m/s.

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During the first two seconds, what therefore is its average velocity? 

answer/question/discussion: ->->->->->->->->->->->-> :

 The average velocity will be 15m/s.

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How far does it therefore rise in the first two seconds?

answer/question/discussion: ->->->->->->->->->->->-> :

 It rises 30 meters in the first two seconds.

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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: ->->->->->->->->->->->-> :

 The velocity at one more second will then be -5m/s and after another will be -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: ->->->->->->->->->->->-> :

 The ball would reach it's maximum height right before the ball changes from positive velocity to negative velocity. The height would be 37.5m.

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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: ->->->->->->->->->->->-> :

 The average velocity after the first four seconds is 5m/s. The height is now 20m.

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How high will it be at the end of the sixth second?

answer/question/discussion: ->->->->->->->->->->->-> :

 The average velocity at the 6th second would be -5m/s. TI'm not sure how to get the height though because if you multiplied -5m/s * 6s, you would get a negative. How can I get the height?

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@& The ball could be falling down a well. Negative heights are certainly possible. Your reasoning is therefore correct, and that -30 m is a perfectly good answer.*@

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