AQA A-level PHYSICS 7408/3A Paper 3 Section A Version: 1.0 Final *JUN2374083A01* IB/M/Jun23/E10 7408/3A /QUESTION PAPER & MARKING SCHEME/ [MERGED] Marl( scheme June 2023

/ For Examiner’s Use Question Mark 1 2 3 TOTAL Thursday 15 June 2023 Morning 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 45. • You are expected to use a scientific calculator where appropriate. • A Data and Formulae Booklet is provided as a loose insert. Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature I declare this is my own work. A-level PHYSICS Paper 3 Section A Time allowed: The total time for both sections of this paper is 2 hours. You are advised to spend approximately 70 minutes on this section. 2 *02* IB/M/Jun23/7408/3A Do not write outside the Section A box Answer all questions in this section. 0 1 A stroboscope emits bright flashes of white light. The duration of each flash and the frequency of the flashes can be varied. Table 1 shows information about the stroboscope. Table 1 Minimum Maximum Duration of each flash / μs 60 300 Frequency of flashes / Hz 1 150 The duration of each flash is T1. The time from the start of a flash to the start of the next flash is T2. The duty cycle of a stroboscope is defined as 1 2 T T . 0 1 . 1 What is the maximum duty cycle of the stroboscope? Tick () one box. [1 mark] 6.0 × 10−5 3.0 × 10−4 9.0 × 10−3 4.5 × 10−2 3 *03* Turn over ► IB/M/Jun23/7408/3A Do not write outside the 0 1 box . 2 Figure 1 shows images produced in an experiment in which a bouncing ball is illuminated by a stroboscope. The stroboscope flashes at a constant frequency. Figure 1 Suggest why T1 must be very short for this experiment. [1 mark] Question 1 continues on the next page 4 *04* IB/M/Jun23/7408/3A Do not write outside the box Figure 2 shows the first six images starting with n = 0, where n is the image number. Figure 2 The images are used to determine: H, the vertical distance from the bottom of the ball to the floor when n = 0 h, the vertical distance from the bottom of the ball to the floor for each non-zero value of n. The n = N image is produced at the instant that the ball hits the floor for the first time. For n between 0 and N it can be shown that 2 0 = 2 u n g n H h f f   − +     where u0 is the vertical velocity of the ball when n = 0 g is the acceleration due to gravity f is the frequency of the flashes. 5 *05* Turn over ► IB/M/Jun23/7408/3A Do not write outside the box 0 1 . 3 In order to find g, a graph is plotted with values of H h n − on the y-axis. Suggest what is plotted on the x-axis. Go on to explain how g is determined from this graph. [3 marks] The following data are recorded. H = 1550 mm f = 31.0 Hz The graphical analysis of data from Figure 1 gives g as 9.79 m s−2 . 0 1 . 4 Determine u0. [3 marks] u0 = m s−1 Question 1 continues on the next page 6 *06* IB/M/Jun23/7408/3A Do not write outside the box Figure 3 shows positions of the bottom of the ball for n = 40 to n = 66 In this range of positions, the ball makes contact with the floor for the second and third times. Values of h, the vertical distance from the bottom of the ball to the floor, are plotted on the y-axis. Values of s, the horizontal displacement from a point on the floor below the centre of the n = 0 image, are plotted on the x-axis. Figure 3 7 *07* Turn over ► IB/M/Jun23/7408/3A Do not write outside the 0 1 box . 5 Determine, in mm s−1 , the horizontal velocity of the ball between the second and third contacts of the ball with the floor. [2 marks] horizontal velocity = mm s−1 0 1 . 6 Determine the time between the second and third contacts. Annotate Figure 3 to show your method