course Q_1_12.1 Your course (e.g., Mth 151, Mth 173, Phy 121, Phy 232, etc. ):
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:
Since the 6 kg mass provides more force, the acceleration will occur in the direction of the 5kg mass. In my opinion, the magnitude of this movement will not be tremendous due to the small difference in these masses.
f=ma
f=5kg(9.8m/s)
f=49N
f=6kg(9.8m/s)
58.8N
You haven't given the net force or the acceleration, both of which can be calculated.
You need to choose a positive direction, identify each force as positive or negative (whichever choice you make for the positive direction one force will be positive and the other negative), and calculate the net force.
Having found the net force, you can combine this with the mass of the system to find the acceleration.
#$&*
If you give the system a push so that at the instant of release the 5 kg object is descending at 1.8 meters / second, what will be the speed and direction of motion of the 5 kg mass 1 second later?
answer/question/discussion:
F=ma
F=5kg(9.8m/s + 1.8m/s)
F=58N
I'm assuming that the movement will resume going against the 5kg mass since the force is greater.
9.8 m/s^2 is the acceleration; 1.8 m/s is an initial velocity. The two quantities have different units and cannot be added.
you are given the initial velocity; you will have chosen a positive direction earlier
Is the initial velocity in your chosen positive direction, or opposite that direction? So is it positive or negative?
What therefore is the initial velocity, and what is the acceleration of the system?
#$&*
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 assume they are going in opposite directions, and the system slows temporarily.
#$&*
You are correct in your assumption, but the results need to be quantified.
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