1. A claw hammer is used to pull a nail out of a board. The nail is at a 60 degree angle of to the board, and a force F1 of magnitude 500N applied to the nail is required to pull it from the board. The hammer head contacts the board at point A, which is 0.080m from where the nail enters the board. A horizontal force F2 is applied to the hammer handle at a distance of 0.300m above the board. What magnitude of force F2 is required to apply the required 500N force (F1) to the nail? (You can ignore the weight of the hammer.)

2. In the figure what is the magnitude of the net gravitational force exerted on the 0.100-kg uniform sphere by the other two uniform spheres? The centers of all three spheres are on the same line. In the figure what is the direction of the net gravitational force exerted on the 0.100-kg uniform sphere by the other two uniform spheres?
According to Newton's third law, does the 0.100-kg sphere exert forces of the same magnitude as your answer the first question, but opposite direction, on each of the other two spheres?

3. A particle of mass 3k is located 1.80m from a particle of mass k. Where should you put a third mass K so that the net gravitational force on K due to the two masses is exactly zero.