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gsmtiger18
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Homework Statement
A circular uniform laser beam has a power of P = 3.2 mW and a diameter of d = 8.5 mm. The beam is a form of electromagnetic raditation with both electric and magnetic field components.
(a) Calculate the intensity of the beam in units of W/m^2
(b) Calculate the energy (delta U) delivered in a time of t = .065 s in Joules.
(c) Use the intensity of the beam (I) to calculate the amplitude of the electric field in V/m
(d) The amplitudes of the electric and magnetic fields have a fixed relationship. Based on that relationship use the result of part (c) to calculate the amplitude of the magnetic field (B) in Tesla.I know that the power is P = 3.2 mW, and the diameter is d = 8.5 mm. From this I calculated intensity of the beam, so part (a) is complete. I can multiply that by time to get energy, so part (b) is complete as well. Where I'm running into a problem is somehow finding the electric field without knowing anything but the intensity and the energy in a small window of time. Typical calculations for electric potential energy haven't worked at all.
Homework Equations
delta U = Pt
I = P/A
A = pi*r^2
That's about all I know. Our professor left us totally on our own to learn this material.
The Attempt at a Solution
All I've managed is to calculate the delivered energy in a small window of time and the intensity of the beam.