The average temperature of the surface of the earth is approximately14◦c.

what would the steady-statetemperature of the earth be if there were no greenhouse effect — i. e. if the emissivity of the earth was independent ofwavelength?

give your answer in◦c.

note that the radius of the earth is6.38×106m, and the intensity of sunlightat the earth’s location is1366w/m2.

hint, how much power from the sun would strike a plate with the same radiusas the earth?

how does that power compare to the power that hits the earth?

another hint — i didn’t give you anemissivity. just all it, and if you remember that absorptivity and emissivity are the same, it will cancel out.

Answer: a charge of -1.0  × 10⁻⁴ c must be placed  at x = 26 m.the sign of the charge will be the same sign as the  -4.0  µc charge.======electricstatic force between two point charges  is given by    where k is coulomb's constant,  8.99×10⁹  n·m²/c², q₁ and q₂ are the point charges, and r is the distance between the two point charges.assign positive to q₁let q₁ =  6.0 µc, q₂ = -4.0  µc, q₀ represent the charge at the origin, and q₃ represent this new charge to place.the charge at the origin q₀ would experience the following force f₀₁ from q₁, with r = 6.0 m (note that 1  µc = 10⁻⁶ c)    the force from q₂    the force from q₃    the net force on the origin charge, q₀, has to be zero for no electrostatic forcehaving an equation where k and q₀ can be divided out of the equation will allow us to solve for q₃    isolating:     a charge of -1.0  × 10⁻⁴ c must be placed  at x = 26 m.the sign of the charge will be the same as the  -4.0  µc charge