Solve and show working/reasoning

Unit 7: Torque & Rotation: AP Physics 1 - Conceptual Qs unit 7. SECTION A - Torque and Statics 10 N 1 . A square piece of plywood on a horizontal tabletop is subjected to the two horizontal forces shown above. Where should a third force of magnitude 5 newtons be applied to put the piece of plywood into equilibrium? (A) (B) (C) (D) 30 2. A uniform rigid bar of weight W is supported in a horizontal orientation as shown above by a rope that makes a 30 angle with the horizontal. The force exerted on the bar at point O, where it is pivoted, is best represented by a vector whose direction is which of the following? (A) (B) (C ) - (D) M2 3 . A rod of negligible mass is pivoted at a point that is off-center, so that length 1 , is different from length 12. The figures above show two cases in which masses are suspended from the ends of the rod. In each case the unknown mass m is balanced by a known mass, M, or M2, so that the rod remains horizontal. What is the value of m in terms of the known masses? (A) M, + M2 (B) 1/2(M, + M2) (C) M, M2 (D) VM, M 2 - 2F 3R 4. A system of two wheels fixed to each other is free to rotate about a frictionless axis through the common center of wheels and perpendicular to the page. Four forces are exerted tangentially to the rims of the wheels, as shown abo magnitude of the net torque on the system about the axis is (A) FR (B) 2FR (C) 5FR (D) 14FR