You're viewing 1 free preview question for Physics HL — subscribe to unlock 88 more, plus the Full Question Bank, Mock Papers & Worksheets.Upgrade

Gravitational Fields · Paper 2 — Free Physics HL Practice Questions

What this topic covers

Fields is where gravity, electricity and magnetism finally get shown to be the same trick played three times: a source (mass, charge, or moving charge), a field that falls off as $1/ r^{2}$ or sits uniform between plates, and a potential that tells you the energy cost of moving through it. HL bolts on two whole subtopics that SL never sees — motion in combined electric and magnetic fields, and electromagnetic induction — and a huge fraction of the marks in this theme come from just two calculation types: transformer turns ratios and induced emf from $ΔΦ/Δ t$ . Get those automatic, then spend the rest of your revision on the sign conventions ( $V_{g}$ is always negative), the vector-vs-scalar traps ( $g$ vs $V_{g}$ , $E$ vs $V$ ), and the direction rules (Lenz's law, $q v \times B$ ) that separate a 6 from a 7.

Read the full Fields lesson notes →

1ChallengeSAQ-LGravitational force and field strength9 marksPaper 2~14 min

A team of planetary scientists analyses data from a probe in a circular polar orbit an altitude of

240\,\text{km}

above the surface of Xylos, a planet with no atmosphere. The surface gravitational field strength of Xylos is

g_s = 8.4\,\text{N\,kg}^{-1}

and its radius is

R = 3.20 \times 10^{6}\,\text{m}

. The mass of the probe is

m = 500\,\text{kg}

(a)

Calculate the gravitational force acting on the probe while in orbit. [3 marks]

(b)

State why the gravitational field strength at the orbital altitude is less than

g_s

. [1 mark]

(c)

Calculate the factor by which the gravitational field strength is reduced from the surface value to the orbital altitude. [2 marks]

(d)

The probe must measure the gravitational field strength at its orbital altitude with a fractional uncertainty of no more than

0.5\%

. Using the relationship

g \propto r^{-2}

, evaluate whether knowing the probe's altitude to within

\pm 1\,\text{km}

is sufficient to achieve this precision. [3 marks]

Solutions

Questions 2-89

Unlock these questions with Premium

That's every free question here — 1 of 89.

+88 more questions, plus Mock Papers & Worksheets, are waiting in Premium.

Upgrade