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Worksheet: Blackbody Radiation and Photon Energy


Determine the power intensity of radiation per unit wavelength emitted at a wavelength of 500.0 nm by a blackbody at a temperature of K.

  • A W/m3
  • B W/m3
  • C W/m3
  • D W/m3
  • E W/m3


A 200-W heater emits a 1.50- radiation. Radiation from the heater warms a 4.00-kg body by 2.00 K.

What value of the energy quantum does it emit?

Assuming that the specific heat capacity of the body is 0.83 kcal/kg⋅K, how many photons must be absorbed to warm the body?

  • A
  • B
  • C
  • D
  • E

Assuming that all the radiation that the heater emits is absorbed by the body, how much time is required for the body’s temperature to increase?


Lasers can be used as surgical instruments to vaporize flesh by heating it. A carbon dioxide laser used in surgery emits infrared radiation with a wavelength of 10.6 μm. In 1.00 ms, this laser raised the temperature of 1.00 cm3 of flesh to and evaporated it. Flesh has a latent heat of vaporization of kJ/kg.

How many photons were required to vaporize the flesh?

  • A
  • B
  • C
  • D
  • E

What was the minimum power output during the flash?


An AM radio transmitter radiates W of electromagnetic radiation at a frequency of Hz. How many photons per second does the transmitter emit?

  • A
  • B
  • C
  • D
  • E


In the 1980s, the term picowave was used to describe food irradiation in order to overcome public resistance by playing on the well-known safety of microwave radiation. Find the energy in MeV of a photon having a wavelength of 1.00 picometers.


A photon has an energy of 20.0 keV.

What is this photon’s frequency?

  • A Hz
  • B Hz
  • C Hz
  • D Hz
  • E Hz

What is this photon’s wavelength?

  • A m
  • B m
  • C m
  • D m
  • E m


A photon has the same energy as a proton that is moving at .

What is the wavelength of the photon?

What is the energy of the photon?

What is the kinetic energy of the proton?