An ordinary 3.0 V flashlight bulb draws roughly 0.25 A of current and converts about 1.0% of the electrical power into light (λ = 550 nm). If the flashlight beam initially has a cross-sectional area of 10 cm2:
(a) How many photons are emitted per second?
(b) How many photons are found in a cubic meter of the beam?
(c) What is the radiant emittance (W cm-2) of the beam as it leaves the flashlight?