DHS 2020 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 2 October 2020 2 hours 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, wher e appropriate. Section A You are advised not to spend more than 30 minutes on Section A. There are fifteen 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 1 hour 30 min 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 15 Section B 1 8 2 8 3 8 4 7 5 5 6 12 7 12 s.f. -1 Total 75 This document consists of 23 printed pages and 1 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 Decimal sub-multiples and multiples of units are indicated using a prefix to the unit. Which row gives the sub-multiples or multiples represented by pico (p) and Tera (T)? pico (p) Tera (T) A 10-9 109 B 10-9 1012 C 10-12 109 D 10-12 1012 2 A squash ball hits the wall with an instantaneous speed u at an angle θ from the vertical. It then rebounds from the wall symmetrically with an equal instantaneous speed as shown. What is the direction and magnitude of the change in velocity of the ball respectively? A upwards, 2u cos θ B leftwards, 2u sin θ C rightwards, 2u sin θ D downwards, 2u cos θ θ u θ u wall squash ball

5 3 A skydiver falls from an aircraft that is moving horizontally. Air resistance is not negligible. The vertical component of the velocity of the skydiver is v. The vertical component of the acceleration of the skydiver is a. What are the variations of v and a during the subsequent fall of the skydiver? v a A constant constant B constant decreasing C increasing constant D increasing decreasing 4 Two objects, P and Q, each of mass 1.0 kg, are suspended one below the other from the ceiling of a lift by two light, inextensible strings X and Y as shown below. What are the tensions in X and Y when the lift is accelerating upwards at 2.0 m s-2 ? Take g to be 10 m s-2 for this question.

6 5 An incompressible liquid of density ρ is contained in a vessel of uniform cross-sectional area A. The atmospheric pressure is P. What is the force acting on a horizontal plane of area x, at a depth h in the liquid? A x gh A P ρ+ B ) (PghA +ρ C ) (Pghx +ρ D APghx +ρ 6 The diagram below shows the position of a person’s lower jawbone and a simplified free- body diagram of the forces acting on it. The jawbone has negligible mass. It consists of two straight parts of length 7.0 cm and 4.0 cm making an angle of 130 o with each other. During one particular bite, a force of 45 N is applied by the teeth at the front of the jawbone. What is the force M exerted by the masseter muscle? A 120 N B 140 N C 150 N D 170 N pivot masseter muscle lower jawbone incissors molars pivot 4.0 cm muscle force M 130o 7.0 cm 45 N

7 7 An electric motor produces 120 W of useful mechanical output power. The efficiency of the motor is 60 %. Which row is correct? electrical power input / W waste heat power output / W A 72 48 B 192 72 C 200 72 D 200 80 8 A simple pendulum consists of a bob of mass m at the end of a light and inextensible thread of length L. The other end of the thread is fixed at C. the bob swings through point B with a speed v and just reaches A. What is the tension in the thread when the bob is at position B? A mg B 2 mg C 3 mg D 4 mg L A B C 90˚

8 9 The gravitational field strength on the surface of planet P is one tenth of that on the surface of planet Q. On the surface of P, a body has a mass of 1.0 kg and a weight of 1.0 N. What are the mass and weight of the same body on the surface of planet Q? mass on Q / kg weight on Q / N A 1.0 0.1 B 1.0 10 C 10 10 D 10 100 10 An object placed on a horizontal platform is vibrating vertically in simple harmonic motion with a frequency of 2.0 Hz. The maximum amplitude of oscillation which will allow the object to remain in contact with the platform throughout the motion is A 6.2 cm B 2.5 cm C 1.6 cm D 0.78 cm 11 The density of argon at a pressure of 1.00 x 10 5 Pa and temperature of 300 K is 1.60 kg m-3. What is the root-mean-square speed of the argon molecules at this temperature? A 216 m s-1 B 250 m s-1 C 306 m s-1 D 433 m s-1 12 A 1.50 kg metal block at a temperature of 400 K is placed into a container containing 10.0 kg of water at a temperature of 300 K. The specific heat capacities of water and the block are 4200 J K-1 kg-1 and 2500 J K-1 kg-1 respectively. Assume that the heat capacity of the container is negligible. What is the temperature when they have reached thermal equilibrium? A 308 K B 320 K C 350 K D 700 K

9 13 The internal energy of a fixed mass of an ideal gas depends on A pressure, but not volume or temperature. B temperature, but not pressure or volume. C volume, but not pressure or temperature. D pressure and temperature, but not volume. 14 A gas undergoes the cycle of pressure and volume changes W→X→Y→Z→W as shown in the diagram below. What is the net work done on the gas? A - 900 J B - 300 J C 300 J D 900 J 15 A system absorbs 80 J through heating while doing 10