#$&*
Phy 201
Your 'ball down ramp' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** Ball Down Ramp_labelMessages **
** **
If a ball rolls from an initial state of rest down three ramps with different slopes, the same distance along the ramp each time, do you think the time required to roll the length of the ramp will be greatest or least for the steepest ramp, or will the interval on the steepest ramp be neither the greatest nor the least? Explain why you think you have correctly predicted the behavior of the system.
Your answer (start in the next line):
The steeper the ramp is, the more energy the ball will have and therefore the velocity will be greater. Since the velocity is greater, but the lenght of the ramp is the same, the steeper ramp will have the least time for the ball to roll down it.
#$&*
If we write down the slopes from least to greatest, next to the time intervals observed for those slopes, would you expect the time intervals to be increasing or decreasing, or do you think there would be no clear pattern? Explain why you think you have correctly described the behavior of the numbers in the table.
Your answer (start in the next line):
The time intervals for the least slope would be greater, therefore the intervals would show a pattern of decreasing as the slope increases.
#$&*
Set up the shelf standard ramp on a reasonably level table, using a piece of 30-cm shelf standard and a single domino under the high end of the ramp. Position the dominoes so that the last .5 cm of the ramp extends beyond the point where the ramp contacts the domino,.and do the same in all subsequent setups.
Set the bracket on the table, touching the lower end of the ramp so that a ball rolling down the ramp will strike the bracket..
Mark a point about 3 cm below the top end of the ramp. Place a domino on the ramp to its high end is at this point, and place the ball just above the domino, so the domino is holding it back. Quickly pull the domino away from the ball so the ball begins to roll freely down the ramp. Allow the ball to roll until it strikes the bracket.
The bracket will probably move a little bit. Reset it at the end of the ramp.
Determine how far the ball rolled from release until it struck the bracket.
Now repeat, but this time use the TIMER. The first click will occur at the instant you release the ball, the second at the instant the ball strikes the bracket. Practice until you are as sure as you can be that you are clicking and pulling back the domino at the same instant, and that your second click is simultaneous with the ball striking the bracket.
When you are ready, do 5 trials 'for real' and record your time intervals.
Then reverse the system--without otherwise changing the position of the ramp, place the domino under the left end and position the bracket at the right end.
Time 5 trials with the ramp in this position.
In the space below, give the time interval for each trial, rounded to the nearest .001 second. Give 1 trial on each line, so that you will have a total of 10 lines, the first 5 lines for the first system, then 5 lines for the second system.
Beginning in 11th line give a short narrative description of what your data means and how it was collected.
Also describe what you were thinking, relevant to physics and the experiment, during the process of setting up the system and performing the trials.
Your answer (start in the next line):
1.981
1.887
1.950
1.919
1.669
1.622
1.544
1.684
1.504
1.794
this data was collected by the description given above, clicking the timer at release and then again as the ball hit the bracket. It was done five times in each direction. This data shows that with one domino, the ball takes between one and two seconds to roll down the ramp.
#$&*
Now place two dominoes under the right end and repeat the process, obtaining the time interval for each of 5 trials.
Then place the two dominoes under the left end and repeat once more.
Enter your 10 time intervals using the same format as before.
Your answer (start in the next line):
1.294
1.326
1.529
1.201
1.061
1.170
1.185
1.139
1.2448
1.294
#$&*
Repeat the preceding using 3 dominoes instead of 2. Enter your 10 time intervals using the same format as before.
Your answer (start in the next line):
.904
.905
.811
.967
.1.123
.983
.967
.889
.780
.982
#$&*
Repeat the preceding again, still using the 3 domino setup, but this time place a CD or a DVD disk (or something of roughly similar thickness) on the 'low' end of the ramp. You need time only 5 intervals, but if you prefer you may use 10. Enter your 5 (or 10) time intervals using the same format as before.
Your answer (start in the next line):
.968
1.076
1.014
.983
.998
#$&*
Repeat the preceding one last time, still using the 3 domino setup, but remove the disk and replace it with a piece of paper. You need time only 5 intervals, but if you prefer you may use 10. Enter your 5 (or 10) time intervals using the same format as before.
Your answer (start in the next line):
1.014
.952
.967
.921
.905
#$&*
Do your results support or fail to support the hypotheses you stated in the first two questions, regarding the relationship between time intervals and slopes? Explain.
Your answer (start in the next line):
My results show my hypothesis to be correct. The higher the slope, the less time it takes the ball to travel from one end to the other.
#$&*
How do you think the average velocity of the ball is related to the slope of the ramp? Explain in as much detail as possible.
Your answer (start in the next line):
The higher the ramp gets, the higher the velocity of the ball gets. As we know, velocity is the distance/time. So if the distance is the same, but the time is shorter, the velocity will increase as the time decreases.
#$&*
Speculate on what it is that causes the average velocity on these ramps to change with slope.
Your answer (start in the next line):
The higher the slope, the more energy the ball obtains as it rolls, therefore, it speeds up.
#$&*
How might you verify whether your speculations are indeed valid explanations?
Your answer (start in the next line):
Continue to measure the speed at which the ball rolls down the ramp. I am unsure of ways to calculate enery, but this would be a way to test my speculations.
#$&*
Do your data conclusively show that the disk made a difference?
Your answer (start in the next line):
My data does not show a large difference with the disk, but did have more readings that showed over a second (ex: 1.---)
#$&*
Do your data conclusively show that the piece of paper made a difference?
Your answer (start in the next line):
My data does not show a large difference with the paper.
#$&*
Imagine that someone is placing different objects below the 'low' end of the ramp, and you are timing the ball. Assume that somehow the object placed below the 'low' end is hidden from you in a way that does not interfere with the timing process. Compared to the thickness of the DVD, how thin would the object have to be before you would be unable, using the TIMER, to observe a difference in times down the ramp?
Answer this question in the first line below. Express your answer in multiples or fractions of the thickness of a disk.
Starting in the second line, explain how you came to your conclusion, based on the results you obtained in this experiment. Also discuss how you could modify or refine the experiment, still using the TIMER, to distinguish the effect of the thinnest possible object placed under the 'low end.
Your answer (start in the next line):
My data would not give us an accurate estimate of how the disk changed the times, but I believe something twice the sixe of the disk would show a difference. In order to see this, I believe it would be benificial to use one disk, two disks, etc.to find what thickness caused a noticible change.
#$&*
Had you placed the disk below the 'low' end of the ramp in a 1-domino setup, do you think the difference in times would have been greater or less? Do you think you would be better able distinguish the presence of a thinner object using the 1-domino setup, or the 3-domino setup? Explain your reasoning below:
Your answer (start in the next line):
Had the disk been used on the single domino, I think the difference would have been noticable because it would have been closwer to the thickness of one domino versus the thickness of three. In other words, the disk would have almost evened the ramp, making it almost level. where as with three dominos, it was nowhere close to level.
#$&*
Does the ball's velocity change more or less quickly with the 3-domino setup or the 1-domino setup? Explain as best you can how you could use your results to support your answer.
Your answer (start in the next line):
The ball's velcoity changes more quickly with the 3-domino set-up versus the single domino set-up. I could use my results to show that the velocity of the 3-domino set-up was much igher than the single -domino set-up.
#$&*
Your instructor is trying to gauge the typical time spent by students on these experiments. Please answer the following question as accurately as you can, understanding that your answer will be used only for the stated purpose and has no bearing on your grades:
•Approximately how long did it take you to complete this experiment?
Your answer (start in the next line):
45 minutes
&#Very good data and responses. Let me know if you have questions. &#