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course PHY 231
labanalysis2#$&*
course phy 231
course phy 231i only have one of the 15 cm ramps instead of the 30 cm ramp, is it okay to use that for these experiments instead?
For now, use what you have. But get by an pick up a 30 cm ramp. You will need both for some later experiments.
Brief ball off ramp to flooruses ball, ramp, TIMER, domino
See also Pictures_of_ball_and_ramps, which includes pictures and brief descriptions of basic setups.
Set up the ramp with one end supported by a domino lying on its long edge.
Time the ball traveling down the ramp, from rest, from release until it reaches the end of the ramp. Then time the ball from release until, having traveled down the ramp and fallen off the edge, it reaches the floor. Use your 8-count to determine the most accurate possible results.
At the same time you should be taking steps to observe how far the ball traveled in the horizontal direction after leaving the edge of the ramp.
Report your data:
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I only have the half size ramp, the one that is 15 cm long instead of 30. Is this okay?
From rest to end of ramp: 5 counts
From rest to the floor: 9 counts
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Then repeat, using the TIMER.
Report your data:
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From rest to end of ramp: .65 seconds
From rest to the floor: 1.0 seconds
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Repeat once more, this time clicking the TIMER at the ball's release, at the end of the ramp, and upon striking the floor.
Report your data:
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From release to end of ramp: .61
From release to floor: 1.01
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Describe the steps you took to get the most accurate possible data, and report your data.
I did multiple trials with each scenario and I took the average time that I got, if my times were consistent. I tried to not anticipate my clicking, so I tried to let go of the ball and click at the same time, click when I heard and saw the ball roll off the table, and click again when I heard it thud the ground. My final trial where I clicked three different times was consistent with my other trials, so that gives me confidence in my results
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Analysis:
Be sure to include at least one sample calculation for each question (for example, when asked to find the acceleration for three setups, indicate how you did one of the calculuations, then just give your results for the other two).
For each setup, according to your 8-counts, what was the time in seconds for the ball to travel from one end of the ramp to the other? Explain your calculations, and give your results.
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I got 5 counts, and my 8-count is approximately 1.2 seconds, so by taking 5 and dividing by 8, and then multiplying by 1.2. I get: .75 seconds
From edge to thefloor, I got 4 counts. So by my 8 count being 1.2 seconds, the time should be .6 seconds
Minor point: You didn't actually count the time to the floor. You used the difference of the two quantities you did count, which is 4 counts. The way you stated your response to the current question could mislead the casual reader into thinking that you did count the time from the edge of the ramp to the floor.
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What were the resulting average velocities?
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From beginning of ramp to end of ramp I got 20cm/s..i calculated this by taking distance traveled divided by time. (15/.75)
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my mistake before was I didn't take into account that there is no acceleration in the x direction.
So my new calculation should look the same as before all the “and” symbols except the distance is only the y distance, not the total distance. So it should look like this:
From beginning of ramp to end of ramp I got 3.33 cm/s..i calculated this by taking the vertical distance traveled divided by time. (2.5/.75)
@& 2.5 cm is the vertical displacement of the ball, so 3.33 cm/s would be its vertical velocity. This can be part of the answer to this question, and it's a very relevant and important quantity.
However the ball has an average velocity on the ramp, in the direction of the ramp. What was its displacement along the ramp, and its average velocity along the ramp?*@
The average velocity from the end of the ramp was a little harder. I used two of the constant acceleration equations to come up with s=s0+vot+.5(vf-v0)t
I know the ball traveled 72.4 cm to the floor, I know the time, and by the calculations in the previous question I know the initial velocity to be 6.7 cm/s (3.33*2). So I came with the final velocity to be 226 cm/s. so the average velocity is (226+6.7)(.5)=116 cm/s
@& Your equation would work and is correct. Simplified it would be
s = s0 + (v0 + vf) / 2 * t.
This is clearly equivalent to
s - s0 = (v0 + vf) / 2 * t,
which is the same as
s - s0 = (v0 + vf) / 2 * t, or
`ds = (v0 + vf) / 2 * t.
Since, for uniform acceleration, vAve = (v0 + vf) / 2, this is equivalent to
`ds = vAve * t,
or as I would notate it,
`ds = vAve * `dt..
You don't say what you used for t, but your result appears to be consistent with your time interval of .6 secomds. *@
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The initial velocity for the fall is not 40 cm/s in the direction of the gravitational acceleration. The vertical component of that velocity might be as much as 10 cm/s or so, depending on the angle of the ramp.
Is the 152.4 cm the vertical height of the edge of the ramp? Unlikely if you used a table, but certainly possible of you set the system up on a shelf or something similar.
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What were the resulting average accelerations, assuming acceleration to have been uniform?
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Acceleration from beginning to end of ramp was 33.4 cm/s^2. Since the average velocity was 20, and starting from rest, I know 40=at, so 40/1.2=a
The acceleration from the end of the ramp to the end of the floor is 7.13 m/s^2
I used the constant acceleration s=s0+v0t+.5at^2
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For each setup what was the time according to the TIMER program?
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To the end of ramp: .65 seconds
From ramp end to the floor: .4 seconds
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What were the resulting average velocities?
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From being of ramp to end of ramp: 23 cm/s
From ramp to floor: ((.5)(358+46)=202 cm/s
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What were the resulting average accelerations, assuming acceleration to have been uniform?
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For on the ramp: 71 cm/s^2
From ramp to the floor 16.7 m/s^2
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Describe how it might be possible for someone to 'think' him- or herself into errors on the 8-count.
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Counting faster and slower each time or thinking that they are counting too fast or slow and compensating to give a false actual time
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Describe how it might be possible for someone to 'think' him- or herself into errors using the TIMER.
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Anticipating when to click or clicking to late and/or too early
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What do you estimate to be your percent error on the 8-count?
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I think about 15 percent off
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I'm not sure about some of your calculations. See my notes and see if you're not combining vertical and horizontal quantities in some of the uniform-acceleration equations. If so, correct them and in your revision.
&#Please see my notes and, unless my notes indicate that revision is optional, submit a copy of this document with revisions and/or questions, and mark your insertions with &&&& (please mark each insertion at the beginning and at the end).
Be sure to include the entire document, including my notes.
If my notes indicate that revision is optional, use your own judgement as to whether a revision will benefit you.
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@& See my notes on your inserted work. No need to revise.*@