## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (3rd Edition)

The intensity of electromagnetic waves from the sun just outside the atmosphere of Venus is $2700~W/m^2$ The intensity of electromagnetic waves from the sun just outside the atmosphere of the earth is $1400~W/m^2$ The intensity of electromagnetic waves from the sun just outside the atmosphere of Mars is $610~W/m^2$
The distance from the sun to Venus is $1.08\times 10^{11}~m$. We can find the intensity just outside the atmosphere of Venus. $I = \frac{P}{A}$ $I = \frac{P}{4\pi~R^2}$ $I = \frac{4.0\times 10^{26}~W}{(4\pi)(1.08\times 10^{11}~m)^2}$ $I = 2700~W/m^2$ The intensity of electromagnetic waves from the sun just outside the atmosphere of Venus is $2700~W/m^2$ The distance from the sun to the earth is $1.50\times 10^{11}~m$. We can find the intensity just outside the atmosphere of the earth. $I = \frac{P}{A}$ $I = \frac{P}{4\pi~R^2}$ $I = \frac{4.0\times 10^{26}~W}{(4\pi)(1.50\times 10^{11}~m)^2}$ $I = 1400~W/m^2$ The intensity of electromagnetic waves from the sun just outside the atmosphere of the earth is $1400~W/m^2$ The distance from the sun to Mars is $2.28\times 10^{11}~m$. We can find the intensity just outside the atmosphere of Mars. $I = \frac{P}{A}$ $I = \frac{P}{4\pi~R^2}$ $I = \frac{4.0\times 10^{26}~W}{(4\pi)(2.28\times 10^{11}~m)^2}$ $I = 610~W/m^2$ The intensity of electromagnetic waves from the sun just outside the atmosphere of Mars is $610~W/m^2$