Edexcel A Level Physics Paper 2: Advanced Physics II June 2017 question paper 9PH0/02

Which of the following wave properties is not exhibited by sound waves?

Two identical springs are arranged side by side as shown.

When a force of 20 N is applied, an extension of 8 cm is obtained.

A force of 5 N is applied to one of the springs on its own.

Which of the following is the extension obtained?

A playground swing completes 24 oscillations in 1 minute.

Which of the following is the frequency of the oscillations?

Which of the following is not a similarity between gravitational fields and electric fields?

A data book contains the following information for ethanol.

latent heat of fusion = 109 kJ kg^–1

latent heat of vaporisation = 838 kJ kg^–1

545 J is transferred from a sample of ethanol when it condenses.

Which of the following shows how to calculate the mass of ethanol that condenses?

Four regions A, B, C and D are labelled on the Hertzsprung‑Russell diagram.

Which region includes the position of the Sun?

A black body radiator of temperature T and surface area A has a luminosity L.

Which of the following is the luminosity of a black body radiator with surface area A/2 and temperature 2 T ?

A line in the hydrogen spectrum of a star in the Milky Way galaxy is observed to have a wavelength of 656.3 nm. In a laboratory on Earth this line has a wavelength of 654.9 nm.

Which of the following expressions gives the magnitude of the velocity of the star relative to Earth?

An object is placed 6.5 cm away from a lens of focal length 3.9 cm. An image is formed 9.8 cm from the lens.

Which of the following is the magnification?

An electric iron rated at 2600 W contains a steel plate which is heated to a working temperature of 215C. Room temperature is 18C.

Deduce whether the plate could reach its working temperature in less than 1 minute.

mass of steel plate = 890 g

specific heat capacity of steel = 450 J kg^–1K^–1

The diagram shows two black holes, A and B, orbiting each other.

Assume that the centre of mass C of the system is the centre of a circular orbit for each black hole as shown in the diagram.

Black hole A is in an orbit of radius 2.910¹⁰m and black hole B is in an orbit of radius 3.610¹⁰m. Both orbit with the same period, so the total distance between them is 6.510¹⁰m.

Calculate the force between the black holes.

mass of Sun, M = 1.9910³⁰kg mass of black hole A = 36M mass of black hole B = 29M

By considering the orbit of one black hole about C, determine the period of the orbit.

The distance to astronomical objects relatively close to the Sun is determined using trigonometric parallax. For objects beyond a certain distance standard candles are used.

State what is meant by a standard candle.

Explain why trigonometric parallax is not used beyond a certain distance.

Describe how distances too large for the use of standard candles can be determined.

Nuclear fusion involves small nuclei joining to make larger nuclei. Nuclear fission involves large nuclei splitting to become smaller nuclei. Both of these processes release energy.

The graph shows how the binding energy per nucleon varies with nucleon number for a range of isotopes.

Use the binding energy per nucleon curve to explain how fusion and fission both release energy.

Explain the conditions required to bring about and maintain nuclear fusion.

*15 The diagram shows apparatus used to investigate polarising filters.

The arrows show the orientation of the plane of polarisation of the filters.

Light is incident on filter 1 and the intensity of the light is measured, using the light detector, when the filters are in the positions shown.

Filter 2 is then rotated and the intensity of light is measured for different angles of rotation θ.

The intensity of light measured with no filters present is I₀. The results are shown on the graph.

Explain the effect of the filters on the intensity of light and why the intensity varies as shown.

A student is investigating a ‘Cartesian diver’.

The diver is made from a plastic pipette. When placed in a plastic bottle full of water the diver rises to the top and touches the lid.

Show that the downward force of the lid on the diver is about 0.02 N.

volume of diver = 8.010^–6m³

mass of diver = 0.0059 kg

density of water = 1.010³kg m^–3

When the pressure is increased by squeezing the bottle, water is forced into the diver increasing its weight. The diver sinks, then remains at rest in the position shown.

The volume of air in the empty pipette in part (a) was 8.010^–6m³.

Show that the volume now occupied by the air is about 610^–6m³.

The pressure of the air in the empty pipette in part (a) was 1.0110⁵Pa.

Calculate the pressure of the air in part (b).

A coulombmeter is used to measure charge.

In a laboratory demonstration of the photoelectric effect, a sheet of zinc was placed on top of a coulombmeter and the zinc was given a negative charge.

*(a) The following observations were made: • under normal lighting conditions the charge remained constant • when the zinc was illuminated with ultraviolet light, the magnitude of the charge on the zinc decreased as time passed • when a larger sheet of zinc was used the charge on the zinc decreased more rapidly. In each case the initial charge on the zinc was the same.

Explain these observations.

For one sheet of zinc, the charge at different times was measured.

The following graph was obtained.

A student suggests that this is an exponential decay curve. Explain how this suggestion could be tested.

Light entering a normal eye is refracted by both the cornea and the lens before a focused image is formed on the retina.

It is suggested that the cornea provides 80% of the focusing power of the eye.

Determine whether this is correct.

focal length of cornea = 2.23 cm

focal length of lens for near object = 5.27 cm

Light from a point object forms a focused image on the retina.

The cornea and lens may be treated as a single lens of focal length 1.6 cm that is 2.4 cm from the retina.

Calculate the distance from the point object to this single lens when a focused image is formed on the retina.

A ray of light strikes the front of the cornea at an angle to the normal in air of 15.

Calculate the angle of the ray to the normal in the cornea.

speed of light in air = 3.0010⁸m s^–1

speed of light in cornea = 2.1810⁸m s^–1

People swimming under water often wear goggles. The goggles enable them to see objects under water clearly whereas without goggles objects appear blurred.

Explain why wearing goggles has this effect.

speed of light in water = 2.2510⁸m s^–1

A school science department keeps a sample of potassium chloride to use as a test source for Geiger‑Müller tubes.

Potassium contains 0.012% of the unstable isotope potassium‑40.

Potassium‑40 undergoes β^– decay, producing a stable isotope of calcium.

Complete the nuclear equation for this decay.

A teacher makes some measurements using the potassium chloride test source to determine whether a Geiger‑Müller tube is sufficiently efficient at detecting β radiation.

The potassium chloride sample has a mass of 300 mg. Show that the number of nuclei of potassium‑40 in the sample is about 310¹⁷.

number of potassium nuclei in 1 g of potassium chloride = 8.110²¹

Show that the activity of this sample is about 5 Bq.

half‑life of potassium‑40 = 1.2510⁹ years

With no sample in front of the Geiger‑Müller tube, a count rate of 15 counts per minute is recorded. When the potassium chloride test sample is placed next to the Geiger‑Müller tube 176 counts are recorded in a period of 10 minutes.

A detector is considered efficient if it detects at least 7.5% of beta emissions from the source.

Determine whether this Geiger‑Müller tube can be considered efficient.

Explain a possible reason why only a low proportion of the decays are detected.

The science department also has a sample of strontium‑90. This undergoes beta decay with a half‑life of 29 years.

State why the half‑life of potassium-40 makes the potassium chloride a more suitable material than strontium-90 for the test.

In 2016 scientists at the Laser Interferometer Gravitational‑Wave Observatory (LIGO) announced that gravitational waves had been detected.

The signal they detected is shown on the graph.

Gravitational waves travel at the speed of light.

Determine the mean wavelength of the waves detected between 0.30 s and 0.35 s on the graph.

Gravitational waves alternately compress and stretch matter by very small amounts as they pass through.

The LIGO detector has two arms, at 90° to each other, each 4 km long. As a gravitational wave passes the detector, the arms change length. The detector continuously compares the lengths of the two arms.

An article states that ‘the maximum change in the 4 km length of the arm is about 0.001 times the diameter of a proton’.

Determine whether this statement applies to the gravitational wave shown in the graph.

diameter of proton = 8.810^–16m

In the LIGO detector, any change in the lengths of the arms is detected using a laser beam and photodetector.

The laser beam is split into two at B, one beam travelling to one mirror and the other beam travelling to the other mirror. After reflection at the mirrors, the beams are recombined at B and reach the photodetector. The photodetector measures the intensity of the incident light.

The system is arranged so that when no gravitational waves are present, the beams have a path difference of half a wavelength at the photodetector.

Explain how the photodetector detects very small changes in the length of one arm, when the other arm stays the same length.

The system could be arranged so that when no gravitational waves are present, the beams have zero path difference at the photodetector.

Explain whether using an initial path difference of half a wavelength is a more sensitive way of detecting changes in length than having an initial path difference of zero.