DP Physics (first assessment 2025)

Question EXE.2.HL.TZ0.16

Date	Example questions Example questions	Marks available	[Maximum mark: 7]	Reference code	EXE.2.HL.TZ0.16
Level	HL	Paper	2	Time zone	TZ0
Command term	Determine, Explain	Question number	16	Adapted from	N/A

16.

[Maximum mark: 7]

EXE.2.HL.TZ0.16

(a)

The radius of the dwarf planet Pluto is 1.19 x 10⁶ m. The acceleration due to gravity at its surface is 0.617 m s⁻².

Determine the escape speed for an object at the surface of Pluto.

[4]

Markscheme

$v_{esc} = \sqrt{\frac{2 G M}{r}}$ AND $g = \frac{G M}{r^{2}}$ seen ✓

$v_{esc} = \sqrt{\frac{2 g r^{2}}{r}}$ ✓

Leading to $v_{esc} = \sqrt{2 g r}$ ✓

1.2 km s⁻¹✓

(b)

Pluto rotates about an axis through its centre. Its rotation is in the opposite sense to that of the Earth, i.e. from east to west.

Explain the advantage of an object launching from the equator of Pluto and travelling to the west.

[3]

Markscheme

Object at equator has the maximum linear/tangential speed possible ✓

It therefore has maximum kinetic energy before takeoff (and this is not required from the fuel) ✓

Idea that the object is already moving in direction of planet before takeoff ✓

Syllabus sections