NJC 2022 Prelim P2

[Turn over NATIONAL JUNIOR COLLEGE SENIOR HIGH 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME SUBJECT CLASS REGISTRATION NUMBER PHYSICS Paper 2 Structured Questions Candidate answers on the Question Paper. 9749/02 23 August 2022 2 hours No Additional Materials are required. READ THE INSTRUCTION FIRST Write your subject class, registration number and name in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Answers all questions. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 / 10 2 / 10 3 / 10 4 / 8 5 / 8 6 / 14 7 / 20 Total (80) This document contains 22 printed pages and 2 blank pages.

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4 Answer all the questions in the spaces provided. 1 As a ship is approaching the dock at 45.0 cm s–1, an important piece of landing equipment needs to be thrown to it before it can dock. This equipment is thrown at 15.0 m s –1 at 60.0° above the horizontal from the top of a tower at the edge of the water, 8.75 m above the ship's deck as shown in Fig. 1.1. For this equipment to land at the front of the ship's deck, the distance from the dock to the ship when the equipment is thrown should be D as shown in Fig.1.1 Fig 1.1 (a) Assuming that air resistance is negligible. (i) Show that the time of flight of the equipment is 3.21 s. [1] (ii) Hence, determine the value of D. D = ………………………………………………… m [3] (b) If air resistance is not negligible, comment on whether D should be longer or shorter. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………. [2]

[Turn over 5 (c) Sketch and label clearly on the same axes in Fig 1.2, a graph to show the variation with time of flight t of the vertical component of velocity Vy of the equipment during its flight if (i) air resistance is negligible, (ii) air resistance is not negligible. For both graphs, take upwards direction as positive. Fig 1.2 [4] [Total: 10] Vy / m s–1 t / s 0

6 2 Two blocks travel directly towards each other along a horizontal, frictionless surface. The blocks collide, as illustrated in Fig. 2.1. Fig. 2.1 Block A has mass 3M and block B has mass M. Before the collision, block A moves to the right with speed 0.40 m s–1 and block B moves to the left with speed 0.25 m s–1. After the collision, block A moves to the right with speed 0.20 m s–1 and block B moves to the right with speed v. (a) (i) Use Newton’s laws of motion to