The average intensity of sunlight at earth's surface is approximately 1400 W/m^2 , if the Sun is directly overhead. The average distance between the earth and the sun is 1.50E11 m. What is the average power emitted by the Sun?
Ok so intensity is power over area.
so power is intensity area, how do I get the area?
Am I approaching this problem correctly?
I used 4*pi*r^2 for the Area and got 3.96E26 W for the Power is that right?
Yes, you are approaching the problem correctly. The power emitted by the Sun can be calculated by multiplying the intensity of sunlight by the surface area at which it is received.
To find the area, you need to consider the surface of a sphere that the sunlight is spreading over. The area of a sphere is given by the formula:
A = 4πr^2
In this case, the distance between the Earth and the Sun (r) is given as 1.50E11 m. So you can substitute this value into the formula to find the area.
Once you have the area, you can use the formula:
Power = Intensity * Area
Substitute the given value of intensity (1400 W/m^2) and the calculated value of area into the formula to find the average power emitted by the Sun.