AQA A-Level Physics 2027 Predicted Practice Paper — Paper 1

Answer ALL questions. Write your answers in the spaces provided. You must write down all the stages in your working.

Section A

Short-answer and structured questions. Answer ALL questions.

• 1

  Question SECTION-A1 (6 marks)

  A small block of mass 0.25 kg rests on a horizontal platform that oscillates vertically with simple harmonic motion. The amplitude of the oscillation is 12 mm and the frequency is gradually increased from zero. (a) State the condition, in terms of the acceleration of the platform, for the block to just lose contact with the platform. (1 mark) (b) Calculate the frequency at which the block first loses contact with the platform. Take g = 9.81 m s^-2. (3 marks) (c) Explain at which point in the oscillation cycle the block loses contact, referring to the direction of the platform's acceleration. (2 marks)

  (Total for Question SECTION-A1 is 6 marks)
• 2

  Question SECTION-A2 (7 marks)

  A 470 microfarad capacitor is charged to a potential difference of 9.0 V and then discharged through a 15 kilohm resistor. (a) Calculate the energy stored on the capacitor when fully charged. (2 marks) (b) Calculate the time constant of the discharge circuit. (1 mark) (c) Calculate the potential difference across the capacitor 12 s after discharge begins. (2 marks) (d) Explain why the discharge current decreases with time. (2 marks)

  (Total for Question SECTION-A2 is 7 marks)
• 3

  Question SECTION-A3 (6 marks)

  In a photoelectric experiment, a clean zinc surface of work function 4.3 eV is illuminated with ultraviolet light of wavelength 210 nm. Take h = 6.63e-34 J s, c = 3.00e8 m s^-1 and e = 1.60e-19 C. (a) Calculate the energy of a single photon of this light, in joules. (2 marks) (b) Show that photoelectrons are emitted, and calculate the maximum kinetic energy of an emitted electron in eV. (3 marks) (c) State how, if at all, the maximum kinetic energy of the photoelectrons would change if the intensity of the light were doubled at constant wavelength. (1 mark)

  (Total for Question SECTION-A3 is 6 marks)
• 4

  Question SECTION-A4 (6 marks)

  A car of mass 1200 kg travels around a flat, unbanked circular bend of radius 45 m at a constant speed of 15 m s^-1. (a) Calculate the centripetal acceleration of the car. (2 marks) (b) Calculate the minimum coefficient of friction between the tyres and the road required to keep the car on the bend. Take g = 9.81 m s^-2. (2 marks) (c) The road becomes wet, reducing the available friction. Explain what happens to the car if the driver maintains the same speed. (2 marks)

  (Total for Question SECTION-A4 is 6 marks)
• 5

  Question SECTION-A5 (7 marks)

  A satellite orbits the Earth in a circular orbit at a height of 2.0e6 m above the Earth's surface. The mass of the Earth is 5.97e24 kg, the radius of the Earth is 6.37e6 m, and G = 6.67e-11 N m^2 kg^-2. (a) Show that the orbital radius is approximately 8.4e6 m. (1 mark) (b) Calculate the orbital speed of the satellite. (3 marks) (c) Calculate the period of the orbit. (2 marks) (d) State one reason why a real satellite at this height would eventually need a boost to maintain its orbit. (1 mark)

  (Total for Question SECTION-A5 is 7 marks)
• 6

  Question SECTION-A6 (6 marks)

  Two parallel metal plates are separated by 8.0 mm in a vacuum and connected to a 1500 V supply. (a) Calculate the magnitude of the uniform electric field strength between the plates. (2 marks) (b) An electron is released from rest at the negative plate. Calculate the kinetic energy it gains, in joules, when it reaches the positive plate. Take e = 1.60e-19 C. (2 marks) (c) State and explain how the electric field strength between the plates would change if the plate separation were doubled while the supply voltage was kept constant. (2 marks)

  (Total for Question SECTION-A6 is 6 marks)
• 7

  Question SECTION-A7 (6 marks)

  The nucleus of helium-4 (He-4) has a mass of 4.00151 u. It is made up of 2 protons (mass 1.00728 u each) and 2 neutrons (mass 1.00867 u each). Take 1 u = 931.5 MeV/c^2. (a) Calculate the mass defect of the helium-4 nucleus, in u. (2 marks) (b) Calculate the binding energy of the nucleus, in MeV. (2 marks) (c) Calculate the binding energy per nucleon, in MeV, and state why this quantity is more useful than total binding energy when comparing the stability of different nuclei. (2 marks)

  (Total for Question SECTION-A7 is 6 marks)
• 8

  Question SECTION-A8 (7 marks)

  A sealed rigid container of volume 0.020 m^3 holds an ideal gas at a pressure of 1.5e5 Pa and a temperature of 300 K. Take the molar gas constant R = 8.31 J mol^-1 K^-1 and the Boltzmann constant k = 1.38e-23 J K^-1. (a) Calculate the number of moles of gas in the container. (2 marks) (b) The gas is heated at constant volume until its pressure rises to 2.4e5 Pa. Calculate the new temperature of the gas. (2 marks) (c) Calculate the mean (average) kinetic energy of a single gas molecule at this new temperature. (2 marks) (d) State what happens to the mean square speed of the molecules as a result of this heating. (1 mark)

  (Total for Question SECTION-A8 is 7 marks)
• 9

  Question SECTION-A9 (6 marks)

  A trolley A of mass 0.80 kg moving to the right at 3.0 m s^-1 collides with a stationary trolley B of mass 1.20 kg. After the collision the two trolleys move off together. (a) State the principle of conservation of linear momentum. (1 mark) (b) Calculate the common velocity of the trolleys immediately after the collision. (2 marks) (c) Calculate the total kinetic energy before and after the collision, and hence state whether the collision is elastic or inelastic. (3 marks)

  (Total for Question SECTION-A9 is 6 marks)

Section B

Extended response and synoptic questions. Answer ALL questions.

• 1

  Question SECTION-B1 (10 marks)

  A mass-spring system is used as a vibration sensor. A 0.40 kg mass hangs from a vertical spring of spring constant 64 N m^-1 and is set into vertical simple harmonic motion with an initial amplitude of 50 mm. (a) Show that the natural frequency of oscillation is approximately 2.0 Hz. (3 marks) (b) Calculate the maximum speed of the mass during the oscillation. (3 marks) (c) The system is now lightly damped. Describe how the amplitude and the period of oscillation change over time, and explain the energy change involved. (2 marks) (d) The sensor is mounted on a machine that vibrates. Explain, with reference to resonance, why the machine's driving frequency should be kept well away from 2.0 Hz to avoid damage. (2 marks)

  (Total for Question SECTION-B1 is 10 marks)
• 2

  Question SECTION-B2 (9 marks)

  This question is about the similarities and differences between gravitational and electric fields, and their application to a charged sphere. (a) State two similarities and one difference between gravitational fields and electric fields. (3 marks) (b) An isolated conducting sphere of radius 0.15 m in a vacuum carries a charge of +8.0e-9 C. Take 1/(4*pi*epsilon0) = 8.99e9 N m^2 C^-2. Calculate the electric potential at the surface of the sphere. (2 marks) (c) Calculate the electric field strength at the surface of the sphere and state its direction. (2 marks) (d) Explain why the electric field strength is zero everywhere inside the conducting sphere. (2 marks)

  (Total for Question SECTION-B2 is 9 marks)
• 3

  Question SECTION-B3 (9 marks)

  A sample of a radioactive isotope initially contains 6.0e12 undecayed nuclei. The isotope has a half-life of 8.0 days. (a) Define the term half-life. (1 mark) (b) Calculate the decay constant of the isotope, in s^-1. (3 marks) (c) Calculate the initial activity of the sample, in becquerel. (2 marks) (d) Calculate the number of undecayed nuclei remaining after 24 days, and explain why radioactive decay is described as a random process yet gives a predictable half-life. (3 marks)

  (Total for Question SECTION-B3 is 9 marks)