Sally and Sam are in a spaceship that comes to within 13,000 km of the asteroid Ceres. Determine the force Sally experiences, in N, due to the presence of the asteroid. The mass of the asteroid is 8.7 x 1020 kg and the mass of Sally is 77 kg. For calculation purposes, assume the two objects to be point masses. EN A 25.0 kg child is riding a playground merrygoround. If the child is 2.00 m from the center of the merrygoround and has a constant tangential speed of 2.50 m/s. What is the magnitude of the net centripetal force that is necessary to keep her on the merry-go-round at this radius? l:lN