A certain heat lamp emits 200 W of mostly IR radiation averaging 1500 nm in wavelength. (a) What is the average photon energy in joules? (b) How many of these photons are required to increase the temperature of a person’s shoulder by 2.0ºC , assuming the affected mass is 4.0 kg with a specific heat of 0.83 kcal/kg ⋅ ºC . Also assume no other significant heat transfer. (c) How long does this take?

A certain heat lamp emits 200 W of mostly IR radiation averaging 1500 nm in wavelength. (a) What is the average photon energy in joules? (b) How many of these photons are required to increase the temperature of a person’s shoulder by 2.0ºC , assuming the affected mass is 4.0 kg with a specific heat of 0.83 kcal/kg ⋅ ºC . Also assume no other significant heat transfer. (c) How long does this take?

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter24: Electromagnetic Waves

Section: Chapter Questions

Problem 54P

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