The cloud of interstellar dust and gas that forms a star in known as a
a. red giant
b. white dwarf
c. protostar
d. nebula

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?

Aphoton is absorbed by an electron that is in the n = 3 state of a hydrogen atom, causing the hydrogen atom to become ionized. very far away from the nucleus, the released electron has a velocity of 750,000 m/s. what was the wavelength of the absorbed photon?

While the change in blank will remain the same during a collision, the force needed to bring an object to a stop can be blank if the time if collision is blank