A plane electromagnetic wave travelling along X-direction has electric field of amplitude 300 V/m, directed along the Y-axis (a) - Physics - Electromagnetic Waves

Question

A plane electromagnetic wave travelling along X-direction has
electric field of amplitude 300 V/m, directed along the Y-axis (a)
what is the intensity of the wave? (b) if the wave falls on the
perfectly absorbing sheet of area 3 0m×m, at what rate the
momentum is delivered to the sheet and what is the radiation
pressure exerted on the sheet

Vijay Shankar Yadav · Accepted Answer

Dear Student,
a)we know energy density of the EM wave =12ε0E02=12×8
85×10-12×90000=3
98×10-7Jm-3as here  E0=300V/mand intensityI=energy density×speed of wave=3
98×10-7×3×108=119
4W/m2b)rate of momentum transfered =energy density×cross section =3
98×10-7×3=11
94×10-7Ns  and radiation   pressure=Ic=3
98×10-7N/m2
Regard