Edexcel A Level Physics Paper 2: Advanced Physics II June 2022 question paper 9PH0/02

A skydiver steps out of an aeroplane and falls from rest, towards the ground. Her parachute opens a short time after she reaches terminal velocity.

Which of the following statements is correct for the vertical acceleration a of the skydiver until her parachute opens?

Light travelling in glass of refractive index n_g is incident at a boundary with water of refractive index n_w. The critical angle for the boundary is C. Which of the following expressions is correct for this boundary?

Sound waves can diffract around obstacles as shown in the diagram.

The diffraction effect is

Which of the following is a valid unit for luminosity?

Betelgeuse is a red giant star.

The surface temperature of Betelgeuse is T_B and the surface area of Betelgeuse is A_B. The surface temperature of the Sun is T_S and the surface area of the Sun is A_S. Which row in the table shows a correct comparison of the surface temperature and surface area of Betelgeuse with those of the Sun?

In a particular radioactive decay, there is a mass decrease equivalent to 0.05 u.

Which of the following expressions gives the energy released in MeV?

Air is trapped in a glass tube. When the air is forced into a smaller volume at a constant temperature, the pressure increases.

Which of the following statements about air molecules is a reason why the pressure the trapped air exerts on the tube increases?

Total internal reflection occurs when light is incident on the boundary between medium 1 and medium 2, as shown.

The refractive index of medium 1 is n₁ and the refractive index of medium 2 is n₂. The critical angle for the boundary is C.

Which row of the table is correct?

The focal length and power of a converging glass lens are determined for the lens in air. The lens is then immersed in water.

Which row in the table shows how the focal length and power of the lens change?

A student used a Geiger-Müller (GM) tube to determine a value for the background count. He recorded the count for 2 minutes, every 15 minutes, as shown in the table.

The counts are not the same.

Which of the following is the reason for this?

The lens of a mobile phone camera has a focal length of 4.25 mm. Light is focused onto light sensors at the back of the camera, as shown.

The camera is initially focused on an object in the far distance.

Calculate the displacement of the lens that would be required to focus on an object 25.0 cm from the camera.

State why the lens and the light sensors in a mobile phone camera can be positioned a fixed distance apart.

In February 2021 the spacecraft Perseverance Rover landed on Mars. When the spacecraft was 11.0 km above the surface of Mars, parachutes opened to slow the descent. The parachutes detached from the spacecraft when it was 2.1 km above the surface of Mars.

Calculate the change in gravitational potential energy of the spacecraft during the parachute section of its descent.

mass of spacecraft = 1030 kg mass of Mars = 6.39 10²³kg radius of Mars = 3390 km

Actinium-225 and bismuth-210 are radioactive isotopes. A sample of each isotope is prepared so that each sample has the same number of nuclei initially.

Explain why the activity of each sample would be the same after 10 days.

half-life of actinium-225 = 10 days half-life of bismuth-210 = 5 days

Explain why the long wavelength lines are shifted by a greater amount than the short wavelength lines.

One of the lines in the hydrogen spectrum occurs at a wavelength of 656 nm in the laboratory.

Explain what conclusion can be made from the shift in wavelength of this line in spectrum B. Your answer should include a calculation.

Aluminium is one of the most widely recycled metals. Aluminium cans are heated from room temperature until all the aluminium has melted. The molten aluminium is then used to make new cans. This process uses only 5% of the energy needed to extract aluminium from raw materials.

On a website it is claimed that recycling one aluminium can of mass 14 g saves enough energy to listen to music on a mobile phone continuously for 7 days.

Assess the validity of this claim.

melting point of aluminium = 660 K specific heat capacity of aluminium = 902 J kg⁻¹K⁻¹ specific latent heat of aluminium = 396 kJ kg⁻¹ room temperature = 293 K mobile phone p.d. = 3.7 V mobile phone current = 120 mA

In an investigation of the photoelectric effect, electromagnetic radiation of frequency f was directed onto a metal plate. The maximum kinetic energy E of the photoelectrons emitted from the metal plate was determined. The procedure was repeated for a range of frequencies.

The graph shows how E depended upon f.

Determine a value for the Planck constant, h, in J s.

The table gives data for different metal surfaces.

Deduce which metal was being used in the investigation.

A simple astronomical refracting telescope consists of two converging lenses. Light from a star is brought to a focus by the objective lens and then viewed through an eyepiece lens as shown.

In the arrangement shown, the final image is formed at infinity.

Explain why the separation of the objective and eyepiece lenses is equal to the sum of their focal lengths.

State why the final image is inverted.

Glass lenses used for optical instruments often have an anti-reflective coating. The coating is a thin layer of a transparent substance with refractive index n_c. Light is reflected from the coating surface and from the lens surface as shown. The reflected light interferes destructively.

When a single-layer coating is used, the coating thickness is chosen to eliminate reflections for green light, which is in the middle of the visible spectrum.

Calculate the minimum thickness d of the coating required for the reflection of green light to be eliminated.

frequency of green light = 6.00 10¹⁴Hz

State why white light reflected from coated lenses is seen as purple.

The harp is a musical instrument with many strings, as shown.

All the strings are under tension.

The strings on one type of harp are made from nylon of density 1070 kg m⁻³. One string has a diameter of 1.14 mm.

Show that the mass per unit length μ of the string is about 1.1 10⁻³kg m⁻¹.

When the middle of the string is plucked, a note of frequency 440 Hz is produced.

Calculate the tension in the string.

length of string = 41.0 cm

The graph shows how the Young modulus E of the nylon varies with temperature.

When the harp is played, the temperature of the string increases.

Explain how this temperature change would affect the frequency of the note produced when the string is plucked.

A fine-beam tube is used for investigating properties of electrons.

An electron beam is produced inside a spherical glass bulb. The bulb contains neon gas at a very low pressure.

The neon gas is at a pressure of 1.25 Pa and a temperature of 25 °C.

Calculate the number N of neon atoms inside the bulb.

bulb diameter = 16.0 cm

*(b) Interactions between electrons and the neon atoms in the tube make the beam visible. Part of the spectrum of visible light produced by these interactions is shown.

Explain the process that results in the emission of this spectrum. Your answer should include reference to energy levels in atoms.

A garden ornament consists of a metal flamingo suspended from a spring as shown. The spring is hung from a support using the hook.

The mass of the flamingo is 65 g. When the flamingo is suspended vertically the spring extends by 8.5 cm.

The flamingo is pulled downwards by a small extra displacement and then released. The flamingo undergoes simple harmonic motion vertically.

The instructions state that the flamingo will oscillate with a frequency of 2.5 Hz.

Deduce whether this statement is correct.

After being set into vertical oscillation, the flamingo comes to rest after a short time.

Explain why the flamingo comes to rest.

In a slight breeze the flamingo swings from side to side and behaves as a simple pendulum.

Show that the period of oscillation of the flamingo pendulum is about 2.2 s.

pendulum length = 1.25 m

The amplitude of oscillation of the flamingo pendulum is 7.5 cm.

Calculate the maximum velocity of the flamingo pendulum.

A hundred years ago, a method to determine the age of certain rocks was developed. An unstable isotope of rubidium is present in some rocks when they form. Over time the rubidium decays to a stable isotope of strontium.

Rubidium decays to strontium via β⁻ decay. Complete the nuclear equation representing the decay.

A sample of Moon rock from the Apollo 11 mission was analysed to determine the age of the rock. When the sample was analysed the number of rubidium atoms was N_R and the number of strontium atoms was N_S. As strontium atoms have all been produced from the decay of rubidium, the original number of rubidium atoms in the sample was (N_R + N_S). From the analysis of the sample, it was determined that = 0.0532

Deduce whether this ratio is consistent with the Earth and the Moon forming at the same time.

age of Earth = 4.5 10⁹ years half-life of rubidium isotope = 4.88 10¹⁰ years

Give a reason why the half-life of the rubidium isotope is hard to determine.

Recent investigations suggest that the half-life of the rubidium isotope may be larger than the traditionally accepted value.

Explain how this would affect the ages obtained by this dating method.