An electron in a mercury atom changes from energy level b to a higher energy level when the atom absorbs a single photon with an energy of 3.06ev. determine the energy of the photon, in joules.

Ball b is hanging from an inextensible cord. an identical ball a is released from rest when it is just touching the cord and drops through the vertical distance h a 5 8 in. before striking ball b. assuming e 5 0.9 and no friction, determine the resulting maximum vertical displacement h b of the ball b

It is really hard for me right know

A58-kg boy swings a baseball bat, which causes a 0.140-kg baseball to move toward third base with a velocity of 38.0 m/s.