Power of sunlight on Earth The Sun emits about 3.9 * 1026 J of electromagnetic radiation each second. (a) Estimate the power that each square meter of the Sun’s surface radiates. (b) Estimate the power that 1 m2 of Earth’s surface receives. (c) What assumptions did you make in part (b)? The distance from Earth to the Sun is about 1.5 * 1011 m and the diameter of the Sun is about 1.4 * 109 m

Respuesta :

Answer:

a)6.34 x  [tex]10^{7}[/tex]W/m²

b)1.37 x [tex]10^{3[/tex] W/m²

c) see explanation.

Explanation:

a)The relation of intensity'I' of the radiation and area 'A' is given by:

I= P/A

where P= power of sunlight i.e 3.9 x [tex]10^{26}[/tex] J

and the area of the sun is given by,

A= 4π[tex]R_{sun}[/tex] => 4π[tex](\frac{1.4*10^{9} }{2} )^{2}[/tex]

A=6.15 x [tex]10^{18}[/tex]m²

[tex]I_{sun}[/tex] =  3.9 x [tex]10^{26}[/tex] / 6.15 x [tex]10^{18}[/tex] => 6.34 x  [tex]10^{7}[/tex]W/m²

b) First determine the are of the sphere in order to determine intensity at the surface of the virtual space

A= 4π[tex]R[/tex]

Now R= 1.5 x [tex]10^{11[/tex]m

A=  4π x 1.5 x [tex]10^{11[/tex] =>2.83 x [tex]10^{23[/tex] m²

The power that each square meter of Earths surface receives

[tex]I_{earth[/tex] =   3.9 x [tex]10^{26}[/tex]/2.83 x [tex]10^{23[/tex] =>1.37 x [tex]10^{3[/tex] W/m²

c) in part (b), by assuming the shape of the wavefront of the light emitted by the Sun is a spherical shape so each point has the same distance from the source i.e sun on the wavefront.