DP Physics (first assessment 2025)

Question EXE.2.SL.TZ0.13a

Date	Example questions Example questions	Marks available	[Maximum mark: 2]	Reference code	EXE.2.SL.TZ0.13a
Level	SL	Paper	2	Time zone	TZ0
Command term	Show that	Question number	a	Adapted from	N/A

[Maximum mark: 2]

EXE.2.SL.TZ0.13a

(a)

Show that $T \propto r^{\frac{3}{2}}$ for the planets in a solar system where $T$ is the orbital period of a planet and $r$ is the radius of circular orbit of planet about its sun.

[2]

Markscheme

Equates centripetal force (with Newton’s law gravitation $m r ω^{2} = \frac{G M m}{r^{2}}$ )

AND

$T = \frac{2 π}{ω}$ ✓

leads to $T^{2} = r^{3} \times (\frac{4 π^{2}}{G M})$ hence result ✓

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D. Fields

D. Fields » D.1 Gravitational fields

Question EXE.2.SL.TZ0.13a

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