Posted by **Summer** on Thursday, August 9, 2007 at 8:24pm.

How many joules of sunlight hit Earth per day? I have looked everywhere and can't find an answer!!

The sun emits about 4*10^26 Watt. The flux of solar energy at the Earth is thus about:

F = 4*10^26 Watt/(4 pi R^2)

where R = 149.6*10^9 meters is the Sun-Earth distance:

F = 1422 Watt/m^2

Multiply this by the intercepting cross section of the Earth, which is pi times the square of the radius of the Earth (and *not* 4 pi times radius squared) to obtain the amount of sunlight in joules that hits the Earth per second.

1422 Watt/m^2 * pi (6378*10^3 m)^2 =

1.82*10^17 Joules/second

There are 24*3600 seconds in a day, so about 1.6*10^22 Joules of sunlight hit the Earth per day.

## Answer This Question

## Related Questions

- astrophysics - 1) Every second the Sun outputs 3.90* 10^26 Joules of energy. ...
- astrophysics - 1) Every second the Sun outputs 3.90* 10^26 Joules of energy. ...
- physics - 1. Calculate the speed in m/s at which the Earth revolves about the ...
- Physics - The average energy flux in the sunlight on the Earth is ⟨S&#...
- science - 1. What is the alignment of the Earth, moon, and sun during a lunar ...
- Science - Facts about the sun are? I have 1. the only star in our solar system 2...
- science double check answers - 1. What is the alignment of the Earth, moon, and...
- Chem - The best solar panels currently available are about 13% efficient in ...
- chem - 1. The total power used by humans worldwide is approximately 15 TW (...
- physics - the solar energy arriving at the outer edge of earth's atmosphere from...

More Related Questions