physics need help please?

Question

The Sun delivers an average power of 0.9 W/m2 to the top of Pluto's atmosphere. Find the magnitudes of E max and B max for the electromagnetic waves at the top of the atmosphere.
B max = T
E max = V/m

Answer 1

Ok, remember this :

The intensity of an electromagnetic wave is :

I = 1/2*Eo*c*Em^2

Eo = electric permebeality = 8.85*10^-12

c = 3*10^8 m/s

0.9 = 1/2*8.85*10^-12*3*10^8*Em^2

Em = 678 V/m

And now, remember : E = cB

678 = 3*10^8*B

B = 226*10^-8 Tesla

Hope that helps