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Electromagnetic Waves. Radiation

Problem 4.198

A ball of radius R=50 cmR=50 \mathrm{~cm} is located in a non-magnetic medium with permittivity ε=4.0.\varepsilon=4.0 . In that medium a plane electromagnetic wave propagates, the strength amplitude of whose electric component is equal to Em=200 V/mE_{m}=200 \mathrm{~V} / \mathrm{m}. What amount of energy reaches the ball during a time interval t=1.0min??t=1.0 \mathrm{min?} ?

Reveal Answer
 4.198. Since t≫T, where T is the period of oscillations, W==1/2Vεε0/μ0‾E2mπR2t=5 kJ\begin{aligned} &\text { 4.198. Since } t \gg T, \text { where } T \text { is the period of oscillations, } W=\\ &=1 / 2 V \overline{\varepsilon \varepsilon_{0} / \mu_{0}} E^{2} m \pi R^{2} t=5 \mathrm{~kJ} \end{aligned}
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