DP Physics (last assessment 2024)

Question 21M.2.SL.TZ1.4a.ii

a.ii.

[Maximum mark: 2]

21M.2.SL.TZ1.4a.ii

A planet orbits at a distance d from a star. The power emitted by the star is P. The total surface area of the planet is A.

(a.ii)

The albedo of the planet is $α_{p}$ . The equilibrium surface temperature of the planet is T. Derive the expression

$T = \sqrt[4]{\frac{P (1 - α_{p})}{16 π d^{2} e σ}}$

where e is the emissivity of the planet.

[2]

Markscheme

use of $e σ A T^{4} OR \frac{P}{4 π d^{2}} \times \frac{A}{4} \times (1 - α_{p})$ ✓

with correct manipulation to show the result ✓

Syllabus sections