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Here is a link to the pulley diagram:Upward force F is exerted on the axle of the pulley shown at right. Consider the pulley and string to be massless and the bearing frictionless. Two bodies, one with mass m1 = 1.00 kg and and the other with mass m2 =2.00 kg, are attached to the opposite ends of the string that passes over the pulley. The body m2 is in contact with the horizontal floor.

http://img287.imageshack.us/img287/2904/1711082ao.gif [Broken]

*(a) What is the largest value the force F may have so that m2 remains at rest on the floor?*

I said 20N here (which is wrong) because if m2 is on the floor, there will be a downward force on the pulley of 20N. If that was matched by an upward force of 20N it would cancel out.

*(b) What is the tension in the string if the upward force F is 100 N?*

This would mean that both masses are off the ground. Because of this (relative to the pulley), mass m1 would be accerating upwards at 10 m/s

^{2}. I got this by saying -10N + 20N = 10N, then dividing it by one kilogram. However, this is also incorrect.

*(c) With the tension determined in part (b), what is the acceleration of m1?*

Here I said that the acceleration would be the 10 m/s

^{2}found in part (b) plus 100N/3kg=33.3...m/s

^{2}, for a total upwards acceleration of 43.3 m/s

^{2}.

All of my answers were incorrect and I cannot see why. Does anyone see my errors? Thank you.

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