DHS 2019 JC1 Promos Physics

1 Name: Index Number: Class: DUNMAN HIGH SCHOOL Promotional Examination Year 5 H2 PHYSICS Multiple Choice and Structured Questions Additional Materials: Multiple Choice Answer Sheet 9749 1 October 2019 2 hours 40 minutes READ THESE INSTRUCTIONS FIRST Write your class, index number and name 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 You are advised not to spend more than 40 minutes on Section A. There are twenty questions in this section. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Section B You are advised not to spend more than 2 hours on Section B. Answer all questions. 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. For Examiner’s Use Section A MCQ 20 Section B 1 10 2 10 3 10 4 9 5 10 6 11 7 20 s.f. -1 Total 100 This document consists of 28 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, µo = 4π × 10−7 H m−1 permittivity of free space, εo = 8.85 × 10−12 F m−1 = (1/(36π)) × 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, m e = 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

3 Formulae uniformly accelerated motion, s = ut + 1 2 at2 v2 = u 2 + 2as work done on/by a gas, W = p∆V hydrostatic pressure, p = ρgh gravitational potential, φ = −Gm/r temperature, T/K = T/oC + 273.15 pressure of an ideal gas, p = 21 3 Nm cV <> mean translational kinetic energy of an ideal gas molecule, E = kT2 3 displacement of particle in s.h.m., x = x0 sin ωt velocity of particle in s.h.m., v = v 0 cos ωt = ±ω 2 2x xo − electric current, I = Anvq resistors in series, R = R1 + R2 + . . . resistors in parallel, 1/R = 1/R 1 + 1/R2 + . . . electric potential, V = r Q oπε4 alternating current / voltage, x = x0 sin ωt magnetic flux density due to a long straight wire, B = 0 2 d Iµ π magnetic flux denxity due to a flat circular coil, B = 0 2 N r Iµ magnetic flux density due to a long solenoid, B = 0nIµ radioactive decay, x = x0 exp(−λt) decay constant, λ = 1 2 ln2 t

4 Section A Answer all the questions. 1 The force F experienced by a charge q moving with speed v at an angle θ to a magnetic field of flux density B is given by F = Bqv sin θ. What is the base unit for B? A N C−1 m−1 s rad−1 B kg s−2 A−1 C kg A−1 rad−1 D kg A−1 2 The power P dissipated by a resistor of resistance R is given by VP R= 2 where V is the potential difference across the resistor. Experimental results give the following: V = (6.52 ± 0.08) V R = (18.3 ± 0.4) Ω Calculate the power dissipated with its uncertainty. A (2.3 ± 0.1) W B (2.32 ± 0.05) W C (2.32 ± 0.08) W D (2.323 ± 0.046) W 3 A stone is thrown with a velocity of 26 m s-1 at an angle of 30o above the horizontal. What is the magnitude of the change in velocity from its starting point to the highest point along its path? A 3.5 m s-1 B 13 m s-1 C 22 m s-1 D 26 m s-1

5 4 An object is released from an open door of an aircraft in level flight. It takes three seconds for the object to reach terminal velocity. Which statement about the motion of the object is correct? A The horizontal component of its velocity is constant. B The horizontal component of its acceleration is zero. C The vertical component of its velocity decreases for three seconds. D The vertical component of its acceleration is zero after three seconds. 5 An astronaut throws a ball near the surface of the Moon, where there is no air resistance. The ball’s initial velocity has a vertical component of 8.00 m s -1 and a horizontal component of 4.00 m s-1 as shown. The acceleration of free fall near the surface of the Moon is 1.62 m s-2. What will be the speed of the ball 9.00 s after being thrown? A 7.7 m s-1 B 22.9 m s-1 C 80.4 m s-1 D 96.4 m s-1

6 6 Two objects of masses m1 and m2 are connected by a light rod as shown. The objects are moving with acceleration a, down a smooth slope that is inclined at an angle 300 to the horizontal. What is the tension in the rod? A 0.5m 1a B (m1 + m2)a C (m1 - m2)a D z ero 7 Student A and Student B engage in a game of tug of war. Student A wins the game, and Student B falls forward. Which of the following statements is correct? A The force exerted by Student A on Student B is larger than that exerted by S tudent B on S tudent A. B The frictional forces exerted by the ground on both students are the same. C The force exerted by Student A on Student B is larger than the frictional force exerted by the ground on Student B. D All of the above. . a m1 m2 rod 300

7 8 The three forces acting on a hot -air balloon that is moving vertically are its weight, the air resistance and the upthrust. The hot-air balloon descends vertically at constant speed. The air resistance exerted on the balloon is F. What weight of material must be released from the balloon so that it ascends vertically at the same constant speed? A F B 2 F C 3 F D 4 F 9 A wire W, initially of length L, is fixed at one end and pulled by a force F at the other end. The wire extends by x. Three wires, all identical to wire W, are connected as shown to form a composite wire. The composite wire is fixed at one end and pulled by the same force F at its other end. What is the total extension of the composite wire? A 5 6 x B 4 3 x C 3 2 x D 2 x 10 A car of mass 1.5 × 103 kg travels along a horizontal road at a speed of 20 m s -1. It then accelerates at 0.30 m s-2. At the time it begins to accelerate, the total resistive force acting on the car is 360 N. What total output power is developed by the car as it begins the acceleration? A 1.8 kW B 7.2 kW C 9.0 kW D 16.2 kW F x wire W fixed L F fixed L L L

8 11 A stone is thrown at an initial velocity u at an angle of 30o above the horizontal. Its initial kinetic energy is K. What is the kinetic energy, in term of K, of the stone at the highest point of the motion? A 0 K B 0.50 K C 0.75 K D 0.87 K 12 The motor M in a crane is used to lift a total mass of 1400 kg through a height of 2.0 m at a constant speed of 1.6 m s−1. The motor is 20% efficient. What is the minimum input power to motor M? A 11 kW B 22 kW C 110 kW D 140 kW 13 A radar tower 150 m tall is built at the equator on top of a hill 2850 m high above mean sea level. As a result of the Earth’s rotation, what is the difference in speed between a man at the top of the tower and someone at mean sea level? A 0 m s−1 B 0.011 m s−1 C 0.22 m s−1 D 790 m s−1 2.0 m 1400 kg 1.6 m s−1

9 14 A stone of mass M and weight W is attached to a string and is rotating in a vertical circ