cq_1_071

#$&*

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.

** CQ_1_07.1_labelMessages **

7.1 Seed

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

To find acceleration we have to find the average velocity, use the average velocity to find the final velocity, and then we can find the acceleration:

vAve=2m/0.4s

=3.125m/s

(vf-vi)/2=3.125m/s

vf=6.25m/s

d=vi*t + .5*a*t^2

2m= 0 + .5*a*0.64^2

a=9.77mm/s/s

#$&*

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

We can check this by using the same equation used above to find acceleration, but solve for time:

d=vi*t + .5*a*t^2

5m=0 * 0.5*9.77m/s/s*t^2

t=1.01s

It’s not exact, but it’s within 0.04 cm/s/s

#$&*

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 acceleration found in the first problem was 9.77m/s^2 and when rounded to one decimal place it is 9.8m/s^2, the gravity constant.

#$&*

*#&!

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