EJC 2022 Prelim P3

©EJC 2022 9749/03/J2H2PRELIM/2022 [Turn over EUNOIA JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS 2022 General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CIVICS GROUP 2 1 - REGISTRATION NUMBER PHYSICS Paper 3 Longer Structured Questions 9749/03 August/September 2022 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use an 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 Answer all questions. Section B Answer one question only. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 27 printed pages and 1 blank page. For Examiner’s Use 1 10 2 5 3 13 4 8 5 4 6 10 7 10 Section B 8 9 20 s.f. Total 80

2 ©EJC 2022 9749/03/J2H2PRELIM/2022 Data speed of light in free space, ( )( ) 81 71 0 12 1 0 91 19 34 27 31 e 27 p 11 23 1 A 23 1 7 10 m s 10 H m 10 F m 10 F m 10 C 6 63 10 J s 1 66 10 kg 10 kg 10 kg J K mol 60 1 2 10 3 00 4 8 85 1 36 60 9 11 0 16 8 31 13 o 8 ml 1 J K c. . / e. . . R. N k. G h. u. m m .    − −− −− −− − − − − − −− − −−      = =   = = = = =  = = = = =  11 2 2 2 10 N m 8 kg m s 6 67 1 9 . g. −− − =  = permeability of free space, permittivity of free space, elementary charge, the Planck constant, unified atomic mass constant, rest mass of electron, rest mass of proton, molar gas constant, the Avogadro constant, the Boltzmann constant, gravitational constant, acceleration of free fall,

3 ©EJC 2022 9749/03/J2H2PRELIM/2022 [Turn over Formulae uniformly accelerated motion, ( ) ( ) 2 22 2 0 0 22 0 12 12 0 0 0 0 0 0 1 2 1 2 2 / K / C 273 15 1 3 3 2 sin cos 1 1 1 4 sin 2 2 exp ln2 at u as V p gh Gm r T T . Nmpc V kT x x t v v t xx R / R / R / R QV r x x t B d NB r s ut v Wp t E Bn t Anvq RR xx              =+  = =− =  + = = = = − ++ = + + = = = = = − = =+ = = = = = I I I I work done on/by a gas, hydrostatic pressure, gravitational potential, temperature, pressure of an ideal gas, mean translational kinetic energy of an ideal gas molecule displacement of particle in s.h.m. velocity of particle in s.h.m. electric current, resistors in series, resistors in parallel, electric potential, alternating current/voltage, magnetic flux density due to a long straight wire magnetic flux density due to a flat circular coil magnetic flux density due to a long solenoid radioactive decay, decay constant

4 ©EJC 2022 9749/03/J2H2PRELIM/2022 Section A Answer all the questions in this Section in the spaces provided. 1 (a) (i) State what is meant by gravitational field strength. [1] (ii) State Newton’s law of gravitation and hence, show that the gravitational field strength g at a distance R from a point mass M is given by 2g GM R= [3]

5 ©EJC 2022 9749/03/J2H2PRELIM/2022 [Turn over (b) A star is spherical in shape, has mass 3010 kg6.2 and radius 410 m.2.7 (i) Calculate the average density of the star. average density = …………………………………. kg m-3 [2] (ii) It is found that the density inside a star is non-uniform. State and explain how the density is likely to vary with distance from the centre of the star. [2] (iii) Find the minimum speed needed for a mass of 250 kg at the surface of the star to escape the effects of the gravitational field due to the star. Show your working clearly. speed = …………………………………. m s-1 [2] [Total: 10]

6 ©EJC 2022 9749/03/J2H2PRELIM/2022 2 (a) State what is meant by simple harmonic motion. [1] (b) In a particular video game, players control the movement of characters through obstacle courses. One particular obstacle features a rectangular wall which moves vertically up and down with simple harmonic motion, as shown in Fig. 2.1. The wall is tall such that the character cannot progress with the game by jumping over the wall. The bottom face of the wall touches the ground every 4.0 s, and rises to a maximum height of 1.4 m. (i) Find the speed of the wall when the bottom face of the wall is 0.50 m above the ground. speed = …………………………………. m s-1 [2] (ii) The bottom face of the wall needs to be at least 0.55 m above the ground for the character to pass under successfully. Find the duration of time that the character can pass under, in each cycle of simple harmonic motion. time = …………………………………. s [2] [Total: 5] Fig. 2.1 (not to scale) level ground game play character direction of game progression wall vertical oscillations 1.4 m

7 ©EJC 2022 9749/03/J2H2PRELIM/2022 [Turn over 3 (a) Fig. 3.1 shows a set up that measures the specific latent heat of vaporization of pure water. The measurements in Fig 3.2 were made across 2 separate experiments each lasting for 1.5 minutes. voltmeter reading / V ammeter reading / A mass of condensed water / g 78 5.0 16 60 4.0 10 Fig. 3.2 (i) Show that the specific latent heat of vaporization of water is 2.25 × 106 J kg-1. [2] Fig. 3.1 flask A V heater coolant inlet coolant exhaust water condensed water mass balance d.c. supply

8 ©EJC 2022 9749/03/J2H2PRELIM/2022 (ii) The assumption when using the values provided in Fig 3.2 to determine the specific latent heat of vaporization of water is that the rate of heat loss from the system is constant. Explain why the assumption is valid. [1] (b) At a temperature of 100 °C and a pressure of 1.00 × 105 Pa, steam of mass 1.00 kg occupies a volume of 1.67 m3. In comparison, liquid water of the same mass, at the same temperature and subject to the same external pressure, occupies a volume of 1.04 × 10-3 m3. 1.00 kg of water undergoes phase change from liquid to gas at 100 °C and 1.0 0 × 105 Pa. Using (a)(i), determine the (i) heat supplied to the water, heat supplied = …………………………………. J [2] (ii) work done by the water, work done = …………………………………. J [2] (iii) increase in internal energy of the water. increase in internal energy = …………………………………. J [1]

9 ©EJC 2022 9749/03/J2H2PRELIM/2022 [Turn over (iv) The total potential energy and total kinetic energy of all the molecules in 1.0 kg of liquid wate