PHY 201
Your 'cq_1_03.1' 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 Question 3.1
The problem:
A ball starts with velocity 0 and accelerates uniformly down a ramp
of length 30 cm, covering the distance in 5 seconds.
What is its average velocity?
answer/question/discussion: ****************
vAve='ds/'dt
vAve= 30cm/5sec
vAve= 6 cm/s
If the acceleration of the ball is uniform then its average
velocity is equal to the average of its initial and final
velocities.
You know its average velocity, and you know the initial velocity is
zero.
What therefore must be the final velocity?
answer/question/discussion: ****************
vAve= (initial + final)/2
6 cm/s = (0+x)/2
= x/2
x=6 cm/s * 2
Final velocity = 12 cm/s
By how much did its velocity therefore change?
answer/question/discussion: ****************
If initial is 0 and final is 12, then the velocity changed by 12
cm/s.
At what average rate did its velocity change with respect to clock
time?
answer/question/discussion: ****************
aAve= 'dv/'dt
= 12cm/s / 5 seconds
So the average acceleration is 12/5 or 2.4 cm/s/s
What would a graph of its velocity vs. clock time look like? Give
the best description you can.
answer/question/discussion: **************** With constant acceleration then the
slope would be the same. So that means the slope is 12/5 which is
positive meaning it goes up from left to right. The line will start
at the origin and rise 2.4 units up the y axis for every 1 unit
moved along the x axis.
But do objects really have uniform acceleration down a ramp? I know
the speed increases but I thought that the acceleration would not
stay constant but rather increase expo
On a ramp whose slope doesn't change, in the ideal case where there is no friction, the acceleration would be constant (actually in the ideal case there would be an extremely slight nonlinearity because the 'higher' it is the further it is from the center of the Earth and the less the gravitational force; however in the lab that difference is negligible and other sources of uncertainty would make it irrelevant).
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30 minutes
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You did a great job with this experiment. See my note.