Prelim H2P3

1 Name: _____________________________ ( ) Class: 21 / ______ 2021 JC2 Preliminary Examination PHYSICS Higher 2 9749/03 Paper 3 Longer Structured Questions Thursday 16 September 2021 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class index number and class in the spaces provided above. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. The use of an approved scientific calculator is expected, where appropriate. Section A Answer all questions. Section B Answer one question only. You are advised to spend about one and a half hours on Section A and half an hour on Section B. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. 9749/03/ASRJC/2021PRELIM [Turn Over ANDERSON SERANGOON JUNIOR COLLEGE For Examiner’s Use Paper 1 Total / 30 Paper 2 Total / 80 Paper 4 Total / 55 Paper 3 Total / 80 1 2 3 4 5 6 7 8 Deduction Prelim / 100 CLT Notice Questions set on the Common Last Topic of the syllabus do not form part of the assessment. They will not be marked by the Examiners. Do not answer the following questions: Question 9 on page 22 Turn to the question and cross it out by drawing a line through the question. In Section B you must answer Question 8. There is now no choice of question in this Section. The total time allowed for this Question Paper has not been changed. The total mark allowed for this Question Paper has not been changed. This document consists of 24 printed pages and 0 blank page.

2 Data speed of light in free space c = 3.00  108 m s−1 permeability of free space 0 = 4  10−7 H m−1 permittivity of free space 0 = 8.85  10−12 F m−1 (1/(36))  10−9 F m−1 elementary charge e = 1.60  10−19 C the Planck constant h = 6.63  10−34 J s 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 molar gas constant R = 8.31 J K−1 mol−1 the Avogadro constant NA = 6.02  1023 mol−1 the Boltzmann constant k = 1.38  10−23 J K−1 gravitational constant G = 6.67  10−11 N m2 kg−2 acceleration of free fall g = 9.81 m s−2 9749/03/ASRJC/2021PRELIM

3 Formulae uniformly accelerated motion s= ut + 1 2 at2 v2 = u2 + 2 as work done on/by a gas W= pΔV hydrostatic pressure p= ρgh gravitational potential φ= −Gm r temperature T/K  T/C + 273.15 pressure of an ideal gas p  1 3 Nm V ⟨ c2⟩ mean translational kinetic energy of an ideal gas molecule E= 3 2 kT displacement of particle in s.h.m. x  x0 sin  t velocity of particle in s.h.m. v  v0 cos  t = ±ω√ xo2−x2 electric current I  Anvq resistors in series R = R1 + R2 + … resistors in parallel 1/R = 1/R1 + 1/R2 + … electric potential V = Q 4 πεor alternating current/voltage x = x0 sin  t magnetic flux density due to a long straight wire B  μoI 2 πd magnetic flux density due to a flat circular coil B  μo∋ ¿ 2 r ¿ magnetic flux density due to a long solenoid B  μo∋¿ ¿ radioactive decay x = x0 exp(–t) decay constant   ln 2 t1 2 9749/03/ASRJC/2021PRELIM [Turn Over

4 Section A Answer all the questions in this section in the spaces provided. 1 (a) A delivery company suggests using a remote-controlled aircraft to drop a parcel into the garden of a customer. When the aircraft is vertically above point P on the ground, it releases the parcel with a velocity that is horizontal and of magnitude 5.40 m s –1. The path of the parcel is shown in Fig. 1.1. Fig. 1.1 (not to scale) The parcel travels a horizontal distance of 4.40 m after its release to reach point Q on the horizontal ground. Assume air resistance is negligible. Determine the height h of the parcel above the ground when it is released. h = …………………………….m [2] (b) Another parcel is accidentally released from rest by a different aircraft when it is hovering at a great height above the ground. Air resistance is now significant. (i) On Fig. 1.2, draw arrows to show the directions of the forces acting on the parcel as it falls vertically downwards. Label each arrow with the name of the force. 9749/03/ASRJC/2021PRELIM 5.40 m s–1 4.40 m

5 Fig. 1.2 [1] (ii) By considering the forces acting on the parcel, state and explain the variation, if any, of the acceleration of the parcel as it moves downwards before it reaches constant (terminal) speed. ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….………….... [3] (iii) State and explain the effect of having a larger mass on the terminal velocity of the parcel. ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….………….... [2] (iv) Describe the energy conversion(s) that occur(s) when the parcel is falling through the air 1. before it reaches constant speed ………………………………………………………………………………….................... ………………………………………………………………………………….................... 2. after it reaches constant speed. ………………………………………………………………………………….................... ………………………………………………………………………………….................... [2] [Total: 10] 9749/03/ASRJC/2021PRELIM [Turn Over

6 2 (a) A student suggests that Newton’s third law implies that the weight of a book resting on a table is equal to the support force that the table exerts on the book. Explain why (i) the student is wrong, ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….………….... [2] (ii) the two forces are equal and opposite. ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….………….... [1] (b) Use Newton’s laws to deduce the principle of conservation of momentum. [3] 9749/03/ASRJC/2021PRELIM

7 (c) In space, an object of mass 28 kg travelling with velocity 88 m s–1 collides with a second object of mass 17 kg travelling in the same direction with a velocity of 53 m s–1. The collision is inelastic. After the collision, the 28 kg object continues to move in the original direction but with a velocity of 67 m s–1. Calculate the loss in kinetic energy in the collision. loss in kinetic energy = …………………………….J [3] (d) In (c), the force exerted by the 28 kg object on the 17 kg object will not have a constant value during the time they are in contact with one another. Sketch two graphs on the axes shown in Fig. 2.1 to show how the force varies with time if the collision in (c) is between (i) two steel objects (label this line S), (ii) two rubber objects (label this line R). Fig. 2.1 [2] [Total: 11] 9749/03/ASRJC/2021PRELIM [Turn Over force time0

8 3 (a) Determine the SI base units of the moment of a force. SI base units : ……………………………. [1] (b) A uniform square sheet of card ABCD is freely pivoted by a pin at a point P. The card is held in a vertical plane by an external force in the position shown in Fig. 3.1. The card has weight 0.15 N which may be considered to act at the centre of gravity G. Each side of the card has length 17 cm. Point P lies on the horizontal line AC and is 4.0 cm from corner A. Line BD is vertical. The card is rele