The intensity of sunlight at the Earth’s distance from the Sun is 1370 W/m2.?

SOMEONE ASKED 👇

The intensity of sunlight at the Earth’s distance from the Sun is 1370 W/m2.?

HERE THE ANSWERS 👇

• 1370 W/m^2 is the intensity of sunlight reaching the earth, and is the value of the Poynting vector at the top of the earth’s atmosphere. The pressure exerted by this radiation is Intensity/c where c is the speed of light.

  Check units: W/m^2 = Js^(-1) m^(-2)

  J= N m =>W/m^2= Js^(-1)m^(-2)=Nm^(-1)s^(-1)

  so W/m^2/(m/s) = Nm^(-1)s^(-1)/ms^(-1) = Nm^(-2) = pressure

  so we have verified that the units of intensity/speed of light = units of radiation pressure

  therefore, the force of radiation acting on the earth is:

  force = radiation pressure x area = (intensity/c)xpi R^2

  force = 1370W/m^2 x pi x( 6.37×10^6m)^2/3×10^8m/s

  force = 5.82×10^8 N

  I am presuming that the sun’s gravitational attraction means the magnitude of the solar gravitational force on earth: If that’s the case, the answer is approx 10^22 N:

  F=GMm/r^2

  G=6.67×10^(-11)=6.67e-11

  M=mass sun = 2×10^30kg=2e30

  m=mass earth = 6×10^24kg

  r=earth sun distance = 1.5×10^11m

  F=(6.6e-11)(2e30)(6e24)/(1.5e11)^2 = 3.56e22N

• 7-8 min. (fyi) the variation in time is due to eliptical orbit of earth

• “power=IA=pi (radius earth)^(2)(1370w/m2)=5.82e8 newtons” ??

  If you work it out it comes in Watts. Power is measured in Watt not Newton.