course phy 201
9/28 5 am
Class 090921The following conventions will allow your instructor to quickly locate your answers and separate them from the rest of any submitted document, which will significantly increase the quality of the instructor's feedback to you and to other students.
When answering these questions, give your answer to a question before the &&&&. This is different than my previous request to place your answer after the &&&&.
When doing qa's, place your confidence ratings and self-assessment ratings on the same line as the prompt.
If you don't follow these guidelines you may well be asked to edit your document to make the changes before I can respond to it.
Thanks.
Acceleration vs. ramp slope
If you missed class today you can easily complete this experiment by staying an extra 5 minutes or so next time. It's a familiar situation (ramp supported by a domino lying flat, then on its long side, then its short side). You will be asked to calculate the acceleration of the ball and the slope of the ramp, create a three-point graph, and calculate two graph slopes.
• By lining up dominoes in their proper orientation, as demonstrated in class, determine the slope of your ramp when supported by a domino lying flat, then lying along its longer edge, then along its shorter edge.
• Using your pendulum in the manner you deem most accurate, take observations necessary to find the acceleration of the ball on each ramp. Try to determine the time down the ramp as accurately as possible.
Give your data and an explanation of what they mean:
I forgot to measure the dominos dimensions but based on prior experiments I believe to have the right numbers
Domino: 5 cm long, 2.5 cm wide, 1 cm thick
Pendulum 25 cm long
Domino flat: 5.5 ticks, avg A = 10.9cm/tick /5.5 ticks = 1.98 cm/tick^2
Domino on side: 2.75 ticks = 21.81 cm/tick / 2.75 ticks = 7.93 cm/tick^2
Domino standing tall: 2 ticks = 30 cm/tick / 2 ticks = 15 cm/tick^2
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Graph acceleration vs. ramp slope and give the three graph points you get as a result of your analysis of the data.
(1/30) , 1.98
(1/ 12), 7.93
(1/6), 15
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Find the slope between the first and second point on your graph.
1/20, 5.95
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Find the slope between the second and third point on your graph.
1/12, 7.07
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What do you think is the uncertainty in your time measurements?
Less than .2 ticks
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What do you think is the percent uncertainty in each of your time measurements?
10%
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What do you think is the percent uncertainty in each of your calculated accelerations?
0%
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What do you think is the percent uncertainty in each of your slopes?
0%
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When you analyze your data for this experiment:
For what object are you calculating the acceleration?
Rolling ball
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What events define the beginning and the end of each time interval you are measuring?
Release of the ball, moment ball leaves ramp
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Where is the object at the beginning of the interval and where is it at the end of the interval?
Top of ramp, end of ramp
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What is the displacement between those positions?
30 cm
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Does the displacement depend in any way on the length of the pendulum?
no
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What information do we get from the length of the pendulum?
It gives us a way to convert ticks to seconds. My pendulum (25 cm) takes approximately .5 seconds per tick
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Very good work.