(EJC) 2024 J2 H2 PRELIM QP P2

©EJC 2024 9749/J2H2PRELIM/2024 [Turn over EUNOIA JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS 2024 General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CIVICS GROUP 2 3 - REGISTRATION NUMBER PHYSICS Structured Questions 9749/02 September 2024 2 hours READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number on all the work you hand in. The use of an approved scientific calculator is expected where appropriate. Answer all questions. 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 paper clips, highlighters, glue or correction fluid. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 23 printed pages and 1 blank page. For Examiner’s Use Q1 10 Q2 10 Q3 10 Q4 8 Q5 6 Q6 6 Q7 10 Q8 20 s.f. P2 Total 80

2 ©EJC 2024 9749/J2H2PRELIM/2024 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 10 m s 10 H m 10 F m 10 F m 10 C 6 63 10 J s 1 3 00 4 8 85 1 36 1 60 9 11 1 67 66 10 kg 10 kg 10 kg J K mol 6 02 10 8 31 1 38 mol 10 J K c. . / e h. u. m m . . . R. N k . . G    − −− −− −− − − − − − −− − −−      = = = =   = = = = = = = =  11 2 2 2 10 N m kg m 67 81 s 6 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 2024 9749/J2H2PRELIM/2024 [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 2024 9749/J2H2PRELIM/2024 1 (a) State the two conditions necessary for a system to be in equilibrium. (i) ………………………………………………………………………………………………. (ii) …………………………………………………………………………………………….[2] (b) Explain what is meant by the centre of gravity of a body. ………………………………………………………………………………………………...... [1] (c) A rod AB is hinged to a wall at A. The rod is held horizontally by means of a cord BD, attached to the rod at end B and to the wall at D, as shown in Fig. 1.1. Fig. 1.1 The rod has weight W and the centre of gravity of the rod is at C. The rod is held in equilibrium by a force T in the cord and a force F produced at the hinge. (i) The line of action of the weight W of the rod passes through the cord at point P. Explain why, for the rod to be in equilibrium, the force F produced at the hinge must also pass through point P. ………………………………………………………………………………………………. ………………………………………………………………………………………………. …………………………………………………………………………………………….[2] wall hinge cord rod D A T P B F C   W

5 ©EJC 2024 9749/J2H2PRELIM/2024 [Turn over (ii) It is given that W = 10 N,  = 30 and length AC = 2 3 AB. Calculate 1. tension T, and T = ……………………………….. N [2] 2. angle .  = ………………………………..  [3] [Total: 10]

6 ©EJC 2024 9749/J2H2PRELIM/2024 2 (a) An object of mass 0.80 kg is placed at a distance r from the centre P of a flat disc rotating horizontally with an angular speed . It undergoes circular motion with the disc, as shown in Fig. 2.1. To determine the maximum frictional force acting on the object, the angular speed is slowly increased until the object starts to slide. For different values of r, this value of the angular speed is recorded as max . The variation with 1 r of  2 max is shown in Fig. 2.2. P  r Fig. 2.1 (top view) object disc 5 10 9 8 7 6 / rad2 s−2 5 6 7 8 9 10 / m−1 Fig. 2.2

7 ©EJC 2024 9749/J2H2PRELIM/2024 [Turn over (i) On Fig. 2.1, draw an arrow to show the direction of the frictional force acting on the object at the instant shown. Label this arrow Z. [1] (ii) Explain the direction of the frictional force in (a)(i). ………………………………………………………………………………………………. …………………………………………………………………………………………… [1] (b) (i) Determine the gradient of the line in Fig. 2.2. gradient = ……………………………….. [2] (ii) Suggest the physical significance of the gradient. Show any necessary working. ………………………………………………………………………………………………. …………………………………………………………………………………………… [2] (c) Determine the maximum frictional force acting on the object. maximum frictional force = ………………………………..N [2] (d) Explain why the object starts to slide as angular speed increases. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. ……………………………………………………………………………………………….… [2] [Total: 10]

8 ©EJC 2024 9749/J2H2PRELIM/2024 3 (a) Explain what is meant by (i) a free oscillation, ………………………………………………………………………………………………. …………………………………………………………………………………………… [1] (ii) the natural frequency of an oscillating body. ………………………………………………………………………………………………. …………………………………………………………………………………………… [1] (b) A strip of metal is clamped to the edge of a bench and a mass is hung from its free end as shown in Figure 3.1. Fig. 3.1 object metal strip mass

9 ©EJC 2024 9749/J2H2PRELIM/2024 [Turn over The end of the strip is pulled downwards by 2.0  10−3 m and then released. Fig. 3.2 shows the variation with time t of the displacement y of the end of the strip. Fig. 3.2 (i) On Fig. 3.3, show the corresponding variation with time t of the potential energy Ep of the vibrating system from t = 0 to t = 0.20 s. Assume the vibrating system to have a mass of 200 g. Fig 3.3 [3] -0.003 -0.002 -0.001 0.000 0.001 0.002 0.003 -0.003 -0.002 -0.001 0.000 0.001 0.002 0.003EP 0 -0.002 0.002 y / m 0 0.05 0.10 0.15 0.20 t / s 0 0.05 0.10 0.15 0.20 t / s 0

10 ©EJC 2024 9749/J2H2PRELIM/2024 (ii) On Fig. 3.4, sketch the variation with displac