AQA AS PHYSICS BEST RATING Paper 1 May 2023

AQA AS PHYSICS Paper 1 Wednesday 17 May 2023 Morning Time allowed: 1 hour 30 minutes Materials For this paper you must have: • a pencil and a ruler • a scientific calculator • a Data and Formulae Booklet • a protractor. Instructions • Use black ink or black ball-point pen. • Fill in the boxes at the top of this page. • Answer all questions. • You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. • If you need extra space for your answer(s), use the lined pages at the end of this book. Write the question number against your answer(s). • Do all rough work in this book. Cross through any work you do not want to be marked. • Show all your working. Information • The marks for questions are shown in brackets. • The maximum mark for this paper is 70. • You are expected to use a scientific calculator where appropriate. • A Data and Formulae Booklet is provided as a loose insert. Answer all questions in the spaces provided. box A strong interaction between a negative kaon (K−) and a proton (p) produces an omega-minus (Ω−) particle, a neutral kaon (K0) and an unidentified particle Y. The interaction is: K− + p → Ω− + K0 + Y Table 1 contains information on the particles in this interaction. Table 1 K− p Ω− K0 Y Rest energy / MeV 493.8 938.3 1672 497.8 493.8 Baryon number +1 +1 0 Charge −1e +1e −1e 0 Strangeness −1 0 −3 +1 . Complete Table 1. [2 marks] . Calculate, in J, the rest energy of the Ω−. [2 marks] rest energy = J . Suggest how energy is conserved in this interaction. Refer to the rest energies of the particles in Table 1. [2 marks] box The quark structure of the Ω− particle is sss. The Ω− is unstable. It decays into a proton through a series of decays: Ω− → Ξ0 + π− followed by Ξ0 → Λ0 + π0 followed by Λ0 → p + π− The Ξ0 and Λ0 are both hadrons. . Deduce the quark structure of the Λ0 particle. [4 marks] quark structure of Λ0 = Question 1 continues on the next page Turn over ► The products of the decay series include π0 and π− particles. These particles are unstable and decay. . The π0 decays into gamma photons. Each gamma photon has a wavelength of 1.25 × 10−14 m. box Calculate the energy of one of these photons. [2 marks] energy of photon = J . The negative pion π− decays. Which row shows the particles that could be created in this decay? Tick () one box. [1 mark] μ− + νμ e + v e + ν e + e + e Turn over for the next question DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box Turn over ► box . Figure 2 shows how A and B vary with time at the upper surface. Figure 2 In the layer, the light has a wavelength of 356 nm. The thickness of the layer is 89 nm. Explain why destructive interference occurs at the upper surface for this thickness. [3 marks] box Question 2 continues on the next page *07* Turn over ► box The frequency of the light in Figure 3 is 4.72 × 1014 Hz. box . The phase difference between A and B shown in Figure 3 is 137°. Show that the time interval labelled t in Figure 3 is approximately 8 × 10−16 s. [3 marks] . 89 nm is the minimum thickness that will produce a phase difference of 137° between A and B. Calculate the refractive index of the material of the layer. [4 marks] refractive index = Turn over ► A student sits near a lake on a sunny day. Some sunlight is reflected from the surface of the lake. Sunlight is also reflected from objects submerged beneath the surface of the lake. The light reflected from the surface makes it difficult to see the submerged objects. Sunlight that reflects from the surface of the lake is horizontally polarised. Sunlight that reflects from the submerged objects is unpolarised. The student puts on a pair of Polaroid sunglasses. The amount of light he sees reflected from the surface is significantly reduced. Explain why the student can now see the submerged objects more clearly. In your answer you should: • describe the nature of an unpolarised wave • explain what is meant by polarisation • explain the relative effect of the Polaroid sunglasses on the light reflected from the surface and the light reflected from the submerged objects. box [6 marks]