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PHY 201
Your 'cq_1_12.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** CQ_1_12.1_labelMessages **
Samantha Rogers
PHY 201
Seed 12.1
Masses of 5 kg and 6 kg are suspended from opposite sides of a light frictionless pulley and are released.
• What will be the net force on the 2-mass system and what will be the magnitude and direction of its acceleration?
answer/question/discussion: ->->->->->->->->->->->-> :
5kg * -9.8m/s^2 = 49N
6kg * 9.8m/s^2 = 58.8N
Fnet = 58.8N - 49N = 9.8 Newtons
9.8 N = 11kg * a
9.8N / 11kg = 0.89m/s^2
The side with the 6kg mass will have a greater magnitude and therefore the system will move in the direction of the greater mass
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• If you give the system a push so that at the instant of release the 5 kg object is descending at 1.8 meters / second, what will be the speed and direction of motion of the 5 kg mass 1 second later?
answer/question/discussion: ->->->->->->->->->->->-> :
fnet = m a
velocity = -1.8m/s
`dt = 1s
a = .9m/s^2
`dv = a
vf = v0 + `dv = -1.8m/s + .9m/s = =.9m/s
The 5 kg object will still be defending, but at .9m/s and not 1.8m/s.
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• During the first second, are the velocity and acceleration of the system in the same direction or in opposite directions, and does the system slow down or speed up?
answer/question/discussion: ->->->->->->->->->->->-> :
One second interval: acceleration is positive and velocity remains negative, velocity and acceleration are in opposite directions. System is speeding up.
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The speed at -.9 m/s is .9 m/s, and the speed at -1.8 m/s is 1.8 m/s. The speed is decreasing, not increasing. The system during this interval is slowing, as must be the case when velocity and acceleration are in opposite directions.
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&#This looks good. See my notes. Let me know if you have any questions. &#