A flashlight of intensity 9 , W/cm^2 illumina | vedclass

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(C) Given, intensity of flashlight, $I = 9 \, W/cm^2 = 9 	imes 10^4 \, W/m^2$. Area, $A = 300 \, cm^2 = 3 	imes 10^{-2} \, m^2$. For a perfectly ref

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$18 \, \mu N$

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(C) Given, intensity of flashlight, $I = 9 \, W/cm^2 = 9 	imes 10^4 \, W/m^2$. Area, $A = 300 \, cm^2 = 3 	imes 10^{-2} \, m^2$. For a perfectly reflective surface, the radiation pressure $p$ is given by $p = \frac{2I}{c}$, where $c = 3.0 	imes 10^8 \, m/s$ is the speed of light. Substituting the values: $p = \frac{2 	imes 9 	imes 10^4}{3 	imes 10^8} = 6 	imes 10^{-4} \, N/m^2$. The average force $F$ exerted on the surface is $F = p 	imes A$. $F = (6 	imes 10^{-4} \, N/m^2) 	imes (3 	imes 10^{-2} \, m^2) = 18 	imes 10^{-6} \, N = 18 \, \mu N$.

$A$ flashlight of intensity $9 \, W/cm^2$ illuminates a perfectly reflective surface of area $300 \, cm^2$. The average force exerted on the surface due to the incident light photons is

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