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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 **
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 = 5 kg * 9.8 m/s^2 = 49 N
F2 = 6 kg * 9.8 m/s^2 = 58.8 N
net_f = -F1 + F2 = -49 N + 58.8 N = 9.8 N
a = net_f / m = 9.8 kg * m/s^2 / 11 kg = 0.891 m/s^2 downward on the 6 kg 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: ->->->->->->->->->->->-> :
descending is positive
net_f = 49 N - 58.8 N = -9.8 N
a = net_f / m = -9.8 kg*m/s^2 / 11 kg = -0.891 m/s^2
v0 = 1.8 m/s, 'dt = 1
vf = v0 + a'dt = 1.8 m/s + -0.891 m/s^2(1 s) = 0.909 m/s
The direction is still 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 of the system appear to be in the opposite directions because of the negative acceleration. The system is beginning to slow down.
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&#Very good responses. Let me know if you have questions. &#