cq_1_081

Phy 201

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 = 25 m/s + (-10 m/s/s) * 1s

vf = 25 m/s – 10 m/s

vf = 15 m/s

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

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

vf = v0 + a * dt

vf = 25 m/s + (-10 m/s/s) * 2s

vf = 25 m/s + (-20 m/s)

vf = 5 m/s

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

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

vAve = (vf + v0) / 2

vAve = (5 m/s + 25 m/s) / 2

vAve = 15 m/s

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

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

`ds = vAve * `dt

`ds = 15 m/s * 2s

`ds = 30 m

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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 3rd Second:

vf = v0 + a * `dt

vf = 25 m/s + (-10 m/s/s) * 3s

vf = 25 m/s + (-30 m/s)

vf = -5 m/s/s

After 4th second:

vf = v0 + a * `dt

vf = 25 m/s + (-10 m/s/s) * 4s

vf = 25 m/s + (-40 m/s)

vf = -15 m/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

0 m/s = 25 m/s + (-10 m/s/s) * `dt

-25 m/s = -10 m/s/s * `dt

2.5 s = `dt

`ds = vAve * `dt

`ds = (25 m/s + 0 m/s) / 2 * 2.5 s

`ds = 12.5 m/s * 2.5 s

`ds = 31.25 m

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

vAve = (vf + v0) / 2

vAve = (-15 m/s + 25 m/s) / 2

vAve = 5 m/s

`ds = vAve * `dt

`ds = 5 m/s * 4s

`ds = 20 m

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

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

vf = v0 + a * `dt

vf = 25 m/s + (-10 m/s/s) * 6s

vf = 25 m/s + (-60 m/s)

vf = -35 m/s

vAve = (-35 m/s + 25 m/s) / 2

vAve = -5 m/s

`ds = vAve * `dt

`ds = -5 m/s * 6s

`ds = -30 m

#$&*

Copy and paste your work into the box below and submit as indicated:

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15 minutes

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&#Very good responses. Let me know if you have questions. &#