Phy 231
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.
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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: ->->->->->->->->->->->-> :
f1= 6 kg * 9.8 m/s/s = 58.8 N
f2 = 5 kg * 9.8 m/s/s = 49 N
Fnet = f1 – f2
fnet = 9.8 N
The systems acceleration cant be found with the net force.
5 kg + 6 kg = 11 kg
9.8 N = 11kg * a
a = 0.89 m/s/s
the acceleration is heading downward on the 6kg side
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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: ->->->->->->->->->->->-> :
using what was found in the previous problem:
v0 = 1.8 m/s
m = 11 kg
a = - 0.89 m/s/s
dt = 1 sec
vf = v0 + a * dt
vf = 1.8 m/s + -0.89 m/s/s * 1 sec
vf = 0.91 m/s
The direction of motion of the 5 kg mass 1 second later will be positive 0.91 m/s heading downward.
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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: ->->->->->->->->->->->-> :
The velocity and acceleration are in opposite directions. With the 5kg mass the system is moving down. With the 6kg mass the system is moving up. This means that overall the system is slowing down.
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30 mins
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&#Very good responses. Let me know if you have questions. &#