Question

Using the solar constant, estimate the rate at which the whole Earth receives energy from the Sun. (Hint: Think about the area of the Earth as seen from the Sun)

Answer 1

Answer:

1.475×10²⁴ W

Explanation:

I = Solar constant of the sun = 1362 W/m² (measured using satellites with value 1.3608 ± 0.0005 kW/m² the error is due to fact that solar output is not always constant)

r = Radius of earth = 6371 km = 6371000 m (mean radius)

A = Area of earth = (4/3)×π×r³

=(4/3)×π×6371000³ = 1.083×10²¹ m²

P = I×A

⇒P = 1362×1.083×10²¹

⇒P = 1.475×10²⁴ W

∴ Rate at which the whole Earth receives energy from the Sun is 1.475×10²⁴ W