How many photons of frequency 2.7*10^14 Hertz would be needed to light a 60 Watt light bulb for 1hr?

1 answer

1 watt = 1 J/second.
60 watts is 60 J/second and that for 1 hour is 60 x (60sec/min) x (60min/hour) = 216,000 J/hour is the energy needed to power the bulb.

E of photon = Planck's constant x 2.7E14 = ??
Divide the power needed by the power/photon to find the number of photons. Surprise. It's a huge number.