phy201
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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Seed question 12
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: ->->->->->->->->->->->-> :
F= m * a
F= 5kg * 9.8m/s^2
f= 49 newtons
F= 6kg * 9.8 m/s^2
F= 58.8newtons
Fnet= 58.8 - 49 newtons
Fnet= 9.8 newtons
9.8 newtons = 11kg * a
a= .89 m/s^2
#$&*
If you give the system a push so that at the instant of release the 5 kg object is descending at 1.8 meters / second, what will be the
speed and direction of motion of the 5 kg mass 1 second later?
answer/question/discussion: ->->->->->->->->->->->-> :
VO=1.8m/s
a=9.8m/s^2
'dt= 1s
m= 5kg
Not bad, but you haven't declared a positive direction, and your signs are not consistent with the statement of the problem.
Vf= V0 + a * 'dt
Vf= 1.8m/s + 9.8m/s^2 * 1s
Vf= 11.6m/s
F=m * a
F= 5kg * 9.8m/s^2
F= 49newtons
a= f/m
a=49/5kg
a= 9.8m/s^2
#$&*
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: ->->->->->->->->->->->-> :
I think that the velocity and the speed are in the same directions, the systme is speeding up as it accelerates with gravity.
speed doesn't have a direction; speed is the magnitude of velocity
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about 30 minutes
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You weren't careful enough with positive and negative directions. I think you'll understand the solution as given, but if you don't be sure to ask. Otherwise no revision is requested.
&#Please compare your solutions with the expanded discussion at the link
Solution
Self-critique your solutions, if this is necessary, according to the usual criteria. Insert any revisions, questions, etc. into a copy of this posted document. Mark any insertions with &&&& so they can be easily identified. &#