What formula do i apply to the following/theories? (1) a 0.30 kg mass attached to the end of a string swings in a vertical circle (R=1.6m). At an instant when theta=50 degrees, the tension in the string is 8.0N. what is the magnitude of the resultant force on the mass at this instant? (2) a 4kg block is lowered down a 37 degree incline a distance of 5m from point A to point B. A horizontal force (F=10N) is applied to the block between A and B. the kinetic energy of the block at A is 10J and at B is 20J. How much work is done on the block by the force of friction between A and B? (3)A rock attached to a string swings in a vertical circle. Which free body diagram could correctly describe the force(s) on the rock when the string is in one possible horizontal position? **DIAGRAMS ARE ATTACHED** for all of the above questions.