Electrons in excited hydrogen atoms are in the
n = 3 energy level. how many different photon
frequencies could be emitted as the atoms return
to the ground state?
(1) 1 (3) 3
(2) 2 (4) 4

If you were to drop a rock from a tall building, assuming that it had not yet hit the ground, and neglecting air resistance. what is its vertical displacement (in m) after 6 s?

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?

Abowling ball rolling down the lane toward the pins has gravitational potential energy. a. no b. a lot of c. a little