Radiation Pressure of 75 Watt Bulb at 8 cm

Thread starter FrankJ777
Start date Nov 8, 2008
Tags

Pressure Radiation Radiation pressure

AI Thread Summary

To estimate the radiation pressure from a 75 Watt bulb at 8 cm, one must first calculate the intensity (S) of the light emitted. The relationship between energy (E) and momentum for photons is crucial, as it connects the bulb's wattage to the radiation pressure. The formula P = S/c can be used to derive the pressure once the intensity is known. Understanding how to relate the bulb's power to the energy of emitted photons is essential for solving the problem. The discussion emphasizes the need for clarity on the principles of photon momentum and energy.

Nov 8, 2008

FrankJ777

b]1. Homework Statement [/b]
Estimate the radiation pressure due to a 75 Watt bulb at a distance of 8 cm from the center of the bulb.

Homework Equations

S=(E x B) , P = S/c

The Attempt at a Solution

I'm not sure were to start. How can I determine the value of E from a 75 Watt bulb.

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Nov 8, 2008

mgb_phys

Science Advisor

Homework Helper

You need to know how the momentum and energy of a photon are related to its wavelength.

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