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course PHY 201
9-14 11:30
Report your counts for the five trials with the toy car going in the first direction in the first line below, separated by commas. Report you counts for the five trials with car going in the opposite direction in the second line below, separated by commas.16, 11, 15, 16, 17---cm traveled were 60, 20, 16, 55, 40
13, 16, 16, 22, 22---cm traveled were 35, 40, 40, 60, 80
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Report the five resulting accelerations for the first direction in the first line below, separated by commas, and use the same format to report in the second line the five for the second direction. Starting in the third line show the details of how you found one of your accelerations.
20.8cm/s, 12.4cm/s, 6.31cm/s,19.1cm/s, 12.3cm/s
18.4cm/s, 13.9cm/s, 13.9cm/s, 11.0cm/s, 11.0cm/s
In the previous homework problems, I found 1 of my 8 counts was about 1.2 seconds. In the first example I divided 60cm by 2.4 seconds and got 25cm/s for the average velocity. I then used the formula A=(Vf-V0)/`dt and got A=(50-0)/2.4=20.8cm/s
that would be (50 cm/s -0)/(2.4 s), which gives you 20.8cm/s^2, not 20.8 cm/s.
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How far from the lower end of the ramps did you have to position the two balls in order to synchronize their consecutive time intervals with the time interval for the third ball released from rest at the top of the third ramp?
6.5cm
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You didn't time the intervals for either trial. Suppose that the ball on the third ramp required 3 seconds to travel the 30-cm length of that ramp. What was the acceleration of that ball? Report the acceleration in the first line. Explain how you found it starting in the second line.
10cm/s
The average velocity is 10cm/s (change in position divided by change in clock time) therefore making the initial velocity 0 and the final velocity 20cm/s because the average velocity is only the velocity up to the midpoint of x. Can we then use the formula A=(vf-v0)/`dt. In this case, A=(20cm/s-0cm/s)/3s. A=6.7cm/s
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Assuming the 3-second interval for the ball on the third ramp, what was the time interval for ball released on the first ramp, and what was the resulting acceleration? Report the acceleration in the first line, and explain how you calculated it starting in the second line.
Time interval was .65s. Acceleration was 30.8cm/s
It took 6.5cm for ramp 1 to synchronize with ramp 3. If the ball travels 30cm in 3 seconds, then on average it will travel 6.5cm in .65 seconds. Using the formula A=(Vf-V0)/`dt, we get A=(20-0)/.65.
***However when dividing this formula out I got 30.8cm/s which does not make sense based on the experiment. It doesn’t seem to me that the ball could have been rolling at 30.8cm/s.
If the ball had the same average speed for the 6.5 cm roll as for the 30 cm roll your conclusion would be valid. However it doesn't. It would have a greater average speed on the 30 cm roll, having more time to build up speed.
If two consecutive 6.5 cm rolls, both from rest, take the same time as the 30 cm roll, then how long does it take to roll the 6.5 cm from rest? What therefore is the acceleration for the 6.5 cm interval?
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Are your two results for the accelerations reasonably consistent? Why would you or would you not expect them to be so?
The results I got were not consistent although I know I don’t have the right answer. I would expect them to be reasonably consistent because the average velocities are the same.
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Are your results in any way relevant to the problem of ordering v0, vf, `dv, v_mid_x, v_mid_t and vAve? If so, what conclusions can you draw?
This experiment helped to better understand the order of the different types of velocities. To order them now, I would have the following: v0, v_mid_t, v_mid_x, vf, `dv, vAVE.
*****I’m not sure if I understood the question correctly. If not, please let me know.
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This problem is optional for Phy 201 students. University Physics students should attempt to solve this problem: Use your knowledge of uniformly accelerated motion to answer the following: If the accelerations are uniform on all three ramps, with all three accelerations being equal, then at what position would the balls on the first two ramps need to be placed in order to achieve the desired result?
If all 3 ramps are uniformly accelerated, then the ball on the 1st and 2nd ramp would need to set at 10cm. Unfortunately, this is just a guess and I can’t reason out my answer. I originally thought that the answer could be 15cm but the accelerations are uniform, not the velocities so I don’t think it could be this.
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Good work on most. However you made a wrong assumption on one of the later problems. Check my notes.
&#Please see my notes and 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).
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