If m is 5.00 kg and r is 20.0 cm, calculate the magnitude and direction of the net gravitational force acting on the ball with the mass of 4m in case 2. define the positive direction as pointing to the right, so your answer should have a positive sign if the net force is directed right, and a negative sign if the net force is directed left. note that a number such as 1.23 x 10^-9 can be entered as 1.23e-9 n

The nuclear potential that binds protons and neutrons in the nucleus of an atom is often approximated by a square well. imagine a proton conned in an innite square well of length 105 nm, a typical nuclear diameter. calculate the wavelength and energy associated with the photon that is emitted when the proton undergoes a transition from the rst excited state (n 2) to the ground state (n 1). in what region of the electromagnetic spectrum does this wavelength belong?