cq_1_071

phy201

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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Seed 7.1

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

'ds= 2meters

v0= 0

'dt= .64seconds

'ds= (v0 + vf )/2 * 'dt

vf= 2 'ds - v0 /'dt

vf= (2 * 2m) - 0 m/s / .64s

vf= 4m - 0 m/s / .64s

vf= 6.25 m/s

a= 'dv / 'dt

a= 6.25 m/s- 0m/s / .64s

a= 9.77 m/s^2

#$&*

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

'ds = 5m

'dt = 1.05s

'ds = vave * 'dt

'ds= 3.125m/s * 1.05s

'ds= 3.28m

It's not clear where you got 3.125 m/s.

no this is not consistant uing the final velocity of 6.25m/s starting out initially at 0 in the time given of 1.05 seconds.

#$&*

Are these observations consistent with the accepted value of the acceleration of gravity, which is 9.8 m / s^2?

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

Yes, the ball when dropped from 2 meters had an acceleration rate of 9.8 m/s^2. This is consistent since the ball is free falling.

#$&*

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about 30 minutes

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Your first acceleration is good; not sure how you got the second but the method you used for the first would have worked.

&#Please compare your solutions with the expanded discussion at the link

Solution

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