If the approximate energy of a photon present in an x-ray is 8.0 × 10-15 joules, what's the frequency of the x-ray? given: planck's constant is 6.63 × 10-34 joule·seconds.
(a)1.2 × 1014 hertz
(b)1.2 × 1019 hertz
(c)8.2 × 1018 hertz
(d)8.3 × 1019 hertz

An object has a weight of 500 on earth what is the mass of this object

Acar drives toward the right over the top of a hill, as shown below. which arrow represents the centripetal acceleration? w x y z

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?