NJC 2024 H1 Physics Prelim P2 QP

[Turn over NATIONAL JUNIOR COLLEGE SENIOR HIGH 2 PRELIMINARY EXAMINATION Higher 1 CANDIDATE NAME SUBJECT CLASS REGISTRATION NUMBER PHYSICS Paper 2 Structured Questions Candidate answers on the Question Paper. 8867/02 27 August 2024 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. Section A Answers all questions. Section B Answer any one question. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A 1 / 8 2 / 5 3 / 8 4 / 16 5 / 6 6 / 10 7 / 7 Section B 8 / 20 9 / 20 Total (80) H

2 This document contains 24 printed pages and 4 blank pages.

3 [Turn over Data speed of light in free space, c = 3.00 × 108 m s–1 elementary charge, e = 1.60 × 10–19 C unified atomic mass constant, u = 1.66 × 10–27 kg rest mass of electron, me = 9.11 × 10–31 kg rest mass of proton, mp = 1.67 × 10–27 kg the Avogadro constant NA = 6.02 × 1023 mol–1 gravitational constant G = 6.67 × 10–11 N m2 kg–2 acceleration of free fall, g = 9.81 m s–2 Formulae uniformly accelerated motion, s = ut + at2 v2 = u2 + 2as resistors in series R = R1 + R2 + ….. resistors in parallel 1/R = 1/R1 + 1/R2 + …..

4 Section A Answer all the questions in this section. 1 An object is launched at a speed of 30 m s -1 at an angle of 60 ° above the ground as shown in Fig. 1.1. Ignore air resistance. (a) Show that the time taken for the object to reach its maximum height is 2.65 s. [1] (b) Calculate the time taken for the object to hit the ground. time = ………………… s [1] (c) Hence or otherwise, calculate the horizontal distance travelled by the object from the point of launch to the point it first hits the ground.

5 [Turn over horizontal distance = ………………… m [2] (d) On Fig. 1.2, sketch the variation with time t of the vertical component of the velocity vy from the time it leaves the ground to the time it hits the ground. [2]

6 (e) On Fig. 1.3, sketch the variation with time of (i) the horizontal component of the velocity of the object for the duration of time in flight. Label this line A. [1] (ii) the horizontal component of the velocity of the object for the duration of time in flight if air resistance is not negligible. Label this line B. [1] [Total: 8]

7 [Turn over 2 An aeroplane of mass 1.5 x 10 5 kg moves horizontally with constant velocity. Fig. 2.1 shows the forces exerted on the aeroplane. Fig. 2.1 (a) Calculate the magnitude of the lift and the drag. lift = ….................…….… N [1] drag = ….................…….… N [1] (b) (i) Define torque of a couple. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………….... [1] (ii) The horizontal separation of the lines of action of lift and weight is 0.80 m. Using your answer to (a), determine the vertical separation of the lines of action of the thrust and drag. vertical separation = ….........…….… m [2] [Total: 5]

8 3 (a) State the principle of conservation of linear momentum. ………………………………………………………………………………………………………. ………………………………………………………………………………………………………. ……………………………………………………………………………………………………. [2] (b) Fig. 3.1 shows two discs, A and B, on a frictionless table collide head -on. Disc A has a mass of 0.36 kg and disc B has a mass of 0.18 kg. Before colliding, disc A has a velocity of 0.40 m s1 and disc B a velocity of 0.10 m s -1 in the opposite direction. On colliding they stick together. Fig. 3.1 Calculate (i) the velocity of the discs after the collision. velocity = …………….………… m s -1 [2] direction = ……………………………… [1] (ii) the kinetic energy lost during the collision expressed as a percentage of the initial kinetic energy of the two discs.

9 [Turn over Percentage = …………………[3] [Total: 8] 4 A company rents out tower cranes of many different sizes. A tower crane is illustrated in Fig. 4.1. This type of tower crane is called a flat -top tower crane because the jib and counter jib are horizontal. A crane can be constructed to different arrangements of height, jib and counter -jib length, and balancing load. The size of the base can be varied to cope with different maximum loads lifted by the crane. Note: The masses of the loads in Fig. 4.1 and in Table 4.1 are given in tonnes (t). One tonne is 1000 kg. Fig. 4.1 Distance x is the fixed distance. This is a different distance for each different crane arrangement. Distance y is variable and changes as the load L is moved in and out from the tower, along the jib. Table 4.1 lists information for four different crane arrangements. The maximum load L in tonnes that can be lifted for different distances y from the centre of the tower for each arrangement is also shown. x y counter jib jib tower load L 16.0 t balancing load force due to mass of structure width w 22.0 t 22.0 t

10 Table 4.1 crane arrangement total length of jib and counter jib / m distance x to 16.0 t balancing load / m Maximum load L at different distances y / t y = 30 m y = 52 m y = 75 m A 95.0 17.3 8.48 4.31 2.60 B 75.0 19.4 9.79 5.15 − C 75.0 21.1 10.81 5.77 − D 55.0 22.3 11.53 − − (a) (i) Calculate the weight of the 16.0 t balancing load. weight = ………………………. unit ……….. [2] (ii) Using the data in Table 4.1, explain why there is no detail provided for crane D when y = 52 m. ………………………………………………………………………………………………… …………………………………………………………………………..………………… [1] (b) (i) Show, for crane A, that the load and the balancing load given in the table can never put the crane into equilibrium. ………………………………………………………………………………………………… ………………………………………………………………………………………………… …………………………………………………………………………………………….. [3] (ii) When in use, crane A is in equilibrium. Suggest how this is achieved. ………………………………………………………………………………………………… …………………………………………………………………………………………………