11970.05R 5 Equation 5.1 is the lens equation. 1 = 1 + 1 f u v      Equation 5.1 An experimental arrangement to verify the lens equation is shown in Fig. 5.1. screen metre rule lens illuminated object Fig. 5.1 In this experiment the lens was kept in a fixed position at the 50.0 cm mark on the metre rule. The object position Po was initially at the 100.0 cm mark on the metre rule. The screen was moved until a focused image was produced. The position PI of the screen on the metre rule was recorded in Table 5.1. To get a series of results to verify Equation 5.1, Po was changed. (a) What type of lens must be used in this experiment? [1] 11970.05R [Turn over (b) The results were recorded in Table 5.1. The raw data in Table 5.1 cannot be used directly to verify the lens equation. Add any additional necessary columns and appropriate headings to Table 5.1 that would allow graphical verification of the lens equation. Now complete the row for Po = 100.0 cm. You do not need to complete the table for any of the other Po values [4] Table 5.1 Po / cm PI / cm 1 2 3 Mean 100.0 28.6 28.8 29.4 95.0 27.5 27.2 27.7 90.0 26.0 25.6 25.8 85.0 23.8 24.2 23.5 80.0 20.0 20.5 20.3 (c) Compare the uncertainty in the values of Po and PI. Explain any difference in the uncertainties of the values. [3] 11970.05R 6 A linear air track is a device used to study motion in a low friction environment. Air is pumped through small holes in a long hollow track. This allows gliders, that are lifted just above the surface of the track by the air, to move friction-free along the track. In an experiment to verify the principle of conservation of momentum, two identical gliders were used, one at rest and the other moving towards it at a constant velocity. After the collision both moved together along the remainder of the air track. (a) Suggest how it is ensured that the gliders do not separate after the collision. [1] (b) The air track and two gliders, labelled A and B, are shown in Fig. 6.1. Glider A is moving to the right, glider B is stationary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A B air track card Fig. 6.1 (i) Two light gates, connected to appropriate software, are used to determine the velocity of the card on top of glider A before and after the collision. On Fig. 6.1 mark suitable positions for the light gates. Label the positions 1 for the first light gate and 2 for the second light gate. [2] 11970.05R (ii) What information must be input to the software to allow the velocity to be determined? [1] (c) Show how the principle of conservation of momentum is verified from the results. [3] THIS IS THE END OF THE QUESTION PAPER 11970.05R BLANK PAGE DO NOT WRITE ON THIS PAGE 11970.05R BLANK PAGE DO NOT WRITE ON THIS PAGE Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright holders may have been unsuccessful and CCEA will be happy to rectify any omissions of acknowledgement in future if notified. Examiner Number 246886 DO NOT WRITE ON THIS PAGE For Examiner’s use only Question Number Marks 1 2 3 4 5 6 Total Marks