Electromagnetic wave striking a small pocket mirror

AI Thread Summary
A plane electromagnetic wave with an intensity of 6.00 W/m^2 strikes a pocket mirror of area 40.0 cm^2, prompting questions about momentum transfer and force exerted. The challenge lies in calculating the momentum transferred to the mirror each second, requiring the determination of energy density (U) for accurate results. The relationship between momentum and force is also explored, emphasizing the connection between energy flux and momentum flux in electromagnetic waves. The discussion highlights difficulties in deriving the correct values while seeking clarity on the underlying physics principles. Understanding the relationship between energy and momentum for electromagnetic waves is crucial for solving the problem.
Minihoudini
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Homework Statement


a plane electromagnetic wave of intensity 6.00 W/m^2, moving in the x direction, strikes a small pocket mirror of area 40.0cm^2, held in the yz plane.
(a) what momentum does the wave transfer to the mirror each second?
(b) find the force that the wave exerted on the mirror?
(c) explain the relationship between a and b


Homework Equations


I know how to get (b) and (c) but the first one is giving me the most trouble. I need help find U in order to get momentum from p= U/c


The Attempt at a Solution



given S I tried to calculate E and B to find Ue and Ub. I used I= E^2/2(mu)c arranged to be E= Sqrt and i used a few others to try to find U but nothing has been working. its telling me that the answer is 1.60 x 10^-10. I am getting answers close to the answer but not the answer.
 
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How does energy flux (S) relate to momentum flux?
 
I meant I
 
Minihoudini said:
I meant I
Same thing. How does energy relate to momentum for an EM wave?
 

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