Physics 9702/42 — October/November 2020

Cambridge A-Level · A Level Structured Questions · worked solutions for every part, with the mark scheme

questions

100

marks

120

minutes

Topics Gravitational Fields · Quantum Physics · Magnetic Fields · Motion in a Circle · Thermodynamics · Ideal Gases · +7 more

Q1Gravitational FieldsMotion in a CircleFree sample

(a)

Define gravitational potential at a point.

(b)

The Earth may be considered to be a uniform sphere of radius $6.4 \times 10^{6}\ \text{m}$ with its mass of $6.0 \times 10^{24}\ \text{kg}$ concentrated at its centre.

A satellite of mass $2.4 \times 10^{3}\ \text{kg}$ is launched from the Equator. It is placed in an equatorial orbit at a height of $5.6 \times 10^{6}\ \text{m}$ above the Earth’s surface.

(i)

Calculate the change $\Delta E_P$ in gravitational potential energy of the satellite for its movement from the surface of the Earth to its position in the equatorial orbit.

$\Delta E_P$ = ______ $\text{J}$

(ii)

Determine the speed of the satellite when in orbit.

speed = ______ $\text{m s}^{-1}$

(c)

Before the satellite in (b) is launched, its speed at the Equator due to the Earth’s rotation is $470\ \text{m s}^{-1}$ .

Suggest why the energy required to launch the satellite depends on whether the satellite, in its orbit, is travelling from west to east or from east to west.

The rest of this paper

11 more questions

Q2Thermodynamics · Ideal Gases10M
Q3Oscillations10M
Q4Communication9M
Q5Electric Fields · Gravitational Fields11M
Q6Capacitance7M
Q7Medical Physics · Quantum Physics6M
Q8Electronics6M
Q9Magnetic Fields8M
Q10Magnetic Fields7M
Q11Quantum Physics10M
Q12Nuclear Physics7M

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