Question

Since force is dp/dt, the force due to radiation pressure reflected off of a solar sail can be calculated as 2 times the radiative momentum striking the sail per second. In the vicinity of Earth's orbit around the Sun, the energy intensity of sunlight is about 1300 W/m2. What is the approximate magnitude of the pressure on the sail? (For comparison, atmospheric pressure is about 105 N/m2.)

Answer 1

8.67×10⁻⁶ N/m²

Step-by-step explanation:

p = Momentum of a photon

E = Energy of a photon

c = Speed of light

I = Intensity of light

Force = dp/dt

`p=(E)/(c)`

`\\\Rightarrow F=((dE)/(dt))/(c)`

As given in question

`F=2((dE)/(dt))/(c)`

Now F/A = Pressure

`P=(2I)/(c)\\\Rightarrow P=(2* 1300)/(3* 10^(8))\\\Rightarrow P=8.67* 10^(-6)\ N/m^2`

∴ Magnitude of the pressure on the sail is 8.67×10⁻⁶ N/m²