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course phy 231
10-23 @ nooni was confused on a few questions within this set of class notes
Deflection of ball down ramp from path
`qx001. How far did the ball travel after leaving the end of the ramp, in the trial without the magnet, and what therefore was its horizontal velocity during the fall, assuming a fall time of .4 second?
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24.5
61.25
cm/s
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`qx002. What is the maximum deflection of the ball, due to the presence of the magnet, from its original straight-line path?
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3 cm to the right
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`qx003. What velocity does the ball therefore attain, in the direction perpendicular to its original straight-line path, as a result of the magnet?
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7.5
cm/s^2 in the right direction
good, but it's cm/s
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`qx004. Assume the ball was close enough to the magnet to have its motion significantly influenced for a distance of 5 centimeters. How long did it take for the ball to travel this distance?
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.1 seconds
im a little confused about how to figure out what you are asking. The distance in the horizontal direction the ball went was 22 cm. So in 5 cm it must have taken .1 seconds if the total fall was .4 seconds?
there wasn't much fall as the ball passed the magnet
how long did it take the ball, which was already off the end of the ramp and moving pretty much in the horizontal direction, to travel the 5 cm past the magnet?
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`qx005. Assume that the ball has a mass of 60 grams. How much momentum did it gain, in the direction perpendicular to its original line of motion, as a result of the magnet?
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1125 g cm/s^2
3cm/.4 seconds, 7.5/.4=18.75, (60)(18.75)=1125
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`qx006. What therefore was the average rate of change of its momentum with respect to clock time, for the 5-cm interval during which the magnet significantly affected its motion?
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im very confused on this question. Im confused on what you mean by momentum?
substitute a = F / m into the 2d equation of motion, rearrange and get F_net `dt = `d( m v ). Impulse = change in momentum.
Impulse is F `dt, momentum is m v.
Generalized, impulse is integral( F dt ), change in momentum by product rule is integral of m dv + v dm.
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`qx007. What were the measurements by which you can calculate the slope of your ramp? What was the slope of the ramp?
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rise of ramp divided by run of the ramp.
I didn't measure the slope of the ramp.
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Acceleration of gravity
`qx008. What was your count for the object dropped in the stairwell? To what time interval in seconds does your count correspond?
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10 counts
1.3 seconds
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`qx009. What was your count for the object dropped in the stairwell? To what time interval in seconds does your count correspond?
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same as “qx008”??
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`qx010. What was the distance the object fell (1 block = 8 inches or about 20 centimeters)?
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18 feet
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`qx011. Using the distance of fall and the time interval in seconds, find the acceleration of the falling object.
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10.65 ft/s
not clear how you got that or if units are correct but I suspect at some point you calculated vAve / `dt, which isn't correct.
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University Physics Students Only
`qx012. Find the initial velocity of the falling ball, based on your measurements of x, y, x0, y0 and your determination of sin(theta) and cos(theta).
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falling ball? Im confused, the ball fell straight down so trig wouldn't need to come into play? Are you referring to another experiment?
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This is for the ball rolling off an inclined ramp and falling to the floor.
`qx013. Find the time of fall of the ball.
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`qx014. Questions about uncertainties:
* What is your estimated uncertainty in the measurements you used to determine sin(theta)?
* What therefore is your uncertainty in sin(theta)?
* What uncertainty does this introduce into your determination of v0?
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`qx015. Based on a single trapezoid of the graph of F vs. x for magnet forces, explain the meaning of the slope and the area of this graph.
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slope: change in F with the proximity of the magnet
area: total force throughout the magnetic forces
You need a more specific response here. What is the meaning of the rise and the run of that trapezoid? What is the meaning of average graph altitude? What is the meaning of the width? From your answers to these questions, you get the meaning of the slope, and the meaning of the area.
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`qx016. Based on a single trapezoid of the graph of PE vs. x for magnet forces, explain the meaning of the slope and the area of this graph.
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wouldn't this be the same as above? Except PE instead of F?
What is the meaning of the rise and the run of that trapezoid? What is the meaning of average graph altitude? What is the meaning of the width? What therefor is the meaning of the area.
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"
You have some good answers, but you've missed some as well.
&#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).
Be sure to include the entire document, including my notes. &#
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