7. A force F is exerted on the axle of the pulley, as shown in the figure below. The pulley and string are massless and there is no friction. Two objects, m = 1.20 kg and m = 1.90 kg, are attached as shown to the opposite ends of the string. The object m, is at rest on the floor. a. What is the largest value the force F may have so that m, will remain at rest on the floor? b. What is the tension in the string if the upward force F is 110 N? c. Referring to (b) above, what is the acceleration of m? m1 m2 a. We start by writing the free body equations for each object. Mass m is being acted on by the tension in the rope T and by its weight m, g. I-mg=ma (1) Mass m is being acted on by the tension in the rope T and by its weight m g. T-mg = ma (2) The pulley has three forces acting on it: two sets of 7 acting downward, and F acting upward. The forces involved in its free body diagram give: F-27=(mass pulley) (acceleration of pulley) = (0)(ap) = 0, giving us our third equation F-27=0 (3)