Edexcel A Level Physics Paper 3: General and Practical Principles in Physics June 2022 question paper 9PH0/03

A student investigated the behaviour of a spring under tension. The spring was hung vertically with a mass holder attached, as shown. The position of the bottom of the mass holder was determined using a metre rule.

The position of the bottom of the mass holder was recorded. The spring was stretched by adding masses to the mass holder and the new positions were determined. The extension of the spring for each mass was calculated.

The results are shown in the table.

Criticise the recording of these results.

Describe how the student should determine the extension of the spring as accurately as possible.

A student was given a box of identical glass microscope slides and asked to determine the density of the glass. She used a micrometer to measure the thickness of one of the slides. She repeated this measurement twice in different places and calculated a mean value for the thickness. The thickness of each slide was approximately 1 mm.

Explain how she should have measured the thickness of the slides in order to minimise the percentage uncertainty.

In her report she wrote

“My value for the mass of the glass slides was precise, because I measured the mass using an electronic balance which was accurate to the nearest 0.01 g. I reduced the effect of random error by repeating the measurement several times.”

Comment on this statement.

It was suggested on an online forum that it would be possible to cook a chicken by repeatedly slapping the chicken with one hand.

It was claimed that the energy transferred to a chicken in 8000 slaps would be sufficient to raise the temperature of the chicken from 23 °C to 165 °C.

In an investigation to test the claim, the effective mass of the hand was taken as 1.75 kg and the speed of the hand just before impact with the chicken as 6.25 m s⁻¹.

Deduce whether the data confirms that 8000 slaps would be sufficient. Assume that no energy is transferred from the chicken to the surroundings.

mass of chicken = 0.875 kg specific heat capacity of chicken = 1770 J kg⁻¹K⁻¹ efficiency of energy transfer from the hand = 65%

Explain whether the assumption made in (a) is realistic.

The diagram shows a metronome, which includes an inverted pendulum, used by musicians to set a tempo. The pendulum oscillates with simple harmonic motion and makes a loud click at regular intervals.

A faulty metronome stopped making a clicking noise. A student tried to check the accuracy of the period T of the metronome, using a stopwatch. The student timed the pendulum as it moved from one extreme of the oscillation to the other.

Explain how the procedure used by the student to determine T could have been improved.

*5 The diagram shows a ‘shaker torch’. When the torch is shaken, a strong magnet moves forwards and backwards through a copper coil, powering a light-emitting diode (LED).

Each time the magnet moves through the coil a current pulse is generated. The coil is connected to a capacitor via a diode, as shown.

Once the torch has been shaken for a few minutes the switch is closed and the LED lights for a short while.

Explain how the shaker torch is able to light the LED.

In an experiment to determine the speed of sound in air a student connected two microphones to an oscilloscope, as shown.

The microphones detect sound from the loudspeaker, converting it to an electrical signal. The signal is displayed on the oscilloscope screen.

Both microphones were initially positioned the same distance from the loudspeaker. The two signals were in phase on the oscilloscope screen. The student slowly moved microphone 2 towards the loudspeaker, until the two signals on the oscilloscope were in phase again. He then measured the distance d between the microphones to determine the wavelength λ of the sound waves.

d = 20.5 cm

Comment on the student’s experimental technique to determine λ.

The oscilloscope trace for the signal from microphone 1 is shown below.

The time base of the oscilloscope was set to 0.20 ms div⁻¹.

Determine a value for the speed of sound in air.

A projectile of mass 65 g is fired vertically upwards into a stationary wooden block of mass 2.400 kg, as shown.

The projectile becomes embedded in the block. They both move vertically upwards through a vertical displacement of 55 cm before momentarily coming to rest.

Calculate the energy dissipated as the projectile hits the block.

Explain how the principle of conservation of energy applies to this collision.

A teacher demonstrated the decay of protactinium using a Geiger-Müller (GM) tube connected to a data logger.

A sealed plastic bottle contains a solvent floating above a liquid containing a uranium salt. Protactinium is produced from the decay of uranium and is present in the solvent as shown.

Deduce whether alpha radiation or beta radiation from the inside of the bottle is detected by the GM tube.

The data logger output is shown below.

Determine the half-life of the protactinium.

Explain why the count rate doesn’t reach zero.

A student is planning to collect data to produce a current-potential difference graph for a filament lamp. Her teacher suggests two circuits that she could use.

Circuit 1 uses a potential divider and circuit 2 uses a variable resistor to vary the potential difference across the filament lamp.

*(a) Discuss the suitability of each circuit to collect the data.

The student sets up the following circuit with the filament lamp. The battery has negligible internal resistance.

The reading on the ammeter is 17.5 mA. Calculate the value of the potential difference (p.d.) across the filament lamp.

p.d. across filament lamp =_........

When a voltmeter with a resistance of 1.5 kΩ is connected as shown, the p.d. across the filament lamp decreases.

Explain why the p.d. across the filament lamp decreases.

A student carried out an experiment to determine the viscosity of some honey. He filled a tall glass cylinder with honey as shown, and timed a ball bearing as it fell through the honey.

The student placed rubber bands near the top and bottom of the cylinder. He started a stopwatch when the ball bearing passed the first band and stopped the stopwatch when the ball bearing passed the second band. He repeated this several times to determine a mean time.

Criticise the student’s method.

The time t for the sphere to fall through a distance of 25.0 cm is shown in the table.

Show that the mean velocity v of the ball bearing is about 0.04 m s⁻¹.

The student had three different types of honey available.

Viscosity η is given by the following expression

radius r of ball bearing = 5.50 × 10⁻³m density of ball bearing ρ_B = 7750 kg m⁻³

Deduce which honey the student used.

A student carried out an experiment to calibrate a thermistor. She connected the thermistor in series with a resistor and a power supply as shown. Then she placed the thermistor in a beaker of hot water and used a thermometer to record the temperature θ of the water.

The student recorded θ and corresponding values of the reading V on the voltmeter as the water cooled.

Explain, making reference to charge carriers, why V increased as the water cooled.

Over a limited temperature range V varies with θ according to the expression

where b and V₀ are constants.

Explain why a graph of lnV against θ would give a straight line.

The student’s data is shown in the table below.

Plot a graph of lnV against θ on the grid opposite. Use the column provided to show any processed data.

Determine values for b and V₀.

In 2011, a tsunami was caused by a massive earthquake centred some distance off the coast of Japan. The tsunami caused a cooling system failure at the Fukushima Nuclear Power Plant. This resulted in a nuclear meltdown and radioactive materials were released into the surroundings.

A reservoir beside one of the reactor buildings contained a large volume of water. In 2013, this water was found to have an extremely high concentration of caesium-137. Caesium-137 is a radioactive isotope of caesium.

Complete the nuclear equation for the decay of caesium-137.

An activity of 2.35 × 10¹² Bq per m³ of water in the reservoir was measured. It is suggested that a safe level for the activity of all water in the reservoir would be 100 Bq.

Calculate the time in years for the caesium-137 to decay to a safe level.

volume of water in reservoir = 5000 m³ half-life of caesium-137 = 30 years

The most common radionuclide amongst the fission products in the fuel was iodine-131, which decays with a half-life of 8.0 days to form a stable isotope of the gas xenon.

Deduce whether enough xenon would have collected in 32 days to exert a pressure of 1.0 10⁵ Pa in a volume of 450 m³. Assume that no gas escapes.

temperature = 20 °C initial number of iodine nuclei = 1.25 × 10²⁸

Buildings in nearby Tohoku University suffered structural damage during the 2011 earthquake.

The graph shows how the acceleration of one of the buildings, measured on the 9th floor, varied with time during the earthquake.

(Source: https://www.sciencedirect.com/science/article/pii/S0038080612001035)

At the time it was reported that during the earthquake the 9th floor of the building displaced by more than 30 cm from its normal position.

Assess the accuracy of this report.

A student used a sonometer to investigate the properties of a stretched wire. The sonometer is a long hollow wooden box.

A steel wire is attached to one end of the box and rests on two wooden bridges. The wire is placed under tension T by hanging a mass from the end of the wire, as shown.

The student placed the base of a vibrating tuning fork in contact with the wire, at one of the bridges. This set the wire into oscillation. He adjusted the position of the other bridge until a single-loop standing wave was produced on the wire between the bridges.

Explain how an antinode is produced at the mid-point of the wire between the bridges.

The student repeated this for a series of tuning forks with different frequencies f. For each fork he measured the distance L between the bridges.

The steel wire, of mass per unit length μ, was placed under tension T by hanging a mass of 2.10 kg from the end of the wire.

State one safety precaution that should be taken when carrying out the investigation.

The student plotted a graph of L² against 1/f². Show that the gradient of this graph is equal to

The student then found a value of μ for a brass wire, using a different method.

He measured the diameter d of the wire using a micrometer.

Explain one technique the student should use when measuring d.

The student obtained the following data.

The stated value of μ for the brass wire used by the student was

Deduce whether the student’s data supports this value for μ.

density of brass = 8700 kg m⁻³ ± 200 kg m⁻³