Assume that a 100W light bulb gives off 2.50% of its energy as visible light. How many photons of visible light are given off in 1.00 min? (Use an average visible wabelength of 550 nm.)
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Assume that a 100W light bulb gives off 2.50% of its energy as visible light. How many photons of visible light are given off in 1.00 min? (Use an average visible wavelength of 550 nm.
http://www.pveducation.org/pvcdrom/prope…
Velocity = frequency * wave length
wave length = 550 * 10^-9 = 5.5 * 10^-7
3 * 10^8 = frequency * 5.5 * 10^-7
Frequency = 5.4545 * 10^14 Hz
The energy is proportional to the frequency of the light.
Energy = Plank’s constant * frequency
Plank’s constant = 6.63 * 10^-34
Energy = 6.63 * 10^-34 * 5.4545 * 10^14 = 3.6163 * 10^-19 Joules per Photon
This is the energy of 1 photon of this specific wave length.
100 watt = 100 joules per second
100 joules/s * 60 s/minute = 6000 joules per minute
2.50 % = 0.025 * 6000 = 150 Joules of energy as photons per minute
150 Joules ÷ 3.6163 * 10^-19 Joules per Photon = 4.148 * 10^20 photons per minute
http://www.pveducation.org/pvcdrom/prope…
Velocity = frequency * wave length
wave length = 550 * 10^-9 = 5.5 * 10^-7
3 * 10^8 = frequency * 5.5 * 10^-7
Frequency = 5.4545 * 10^14 Hz
The energy is proportional to the frequency of the light.
Energy = Plank’s constant * frequency
Plank’s constant = 6.63 * 10^-34
Energy = 6.63 * 10^-34 * 5.4545 * 10^14 = 3.6163 * 10^-19 Joules per Photon
This is the energy of 1 photon of this specific wave length.
100 watt = 100 joules per second
100 joules/s * 60 s/minute = 6000 joules per minute
2.50 % = 0.025 * 6000 = 150 Joules of energy as photons per minute
150 Joules ÷ 3.6163 * 10^-19 Joules per Photon = 4.148 * 10^20 photons per minute