DHS 2021 JC1 Promos Physics (Paper 1)

1 © DHS 2021 9749/01 [Turn over Name: Index Number: Class: DUNMAN HIGH SCHOOL Promotional Examination Year 5 H2 PHYSICS Paper 1 Multiple Choice Questions Additional Materials: Multiple Choice Answer Sheet 9749/01 6 October 2021 40 minutes READ THESE INSTRUCTIONS FIRST Write your class, index number and name at the top of this page. Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. There are twenty questions on this paper. 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. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. The use of an approved scientific calculator is expected, where appropriate. Write your name and class on t he Multiple Choice Answer Sheet. Write and shade the Index Number as follows. For illustration only: A student from class 5C99, with index number 02, should shade “9902”. 9 9 0 2 This document consists of 12 printed pages.

2 © DHS 2021 9749/01 [Turn over 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, me = 9.11 × 10−31 kg rest mass of proton, m p = 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 © DHS 2021 9749/01 [Turn over 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 = x 0 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/R1 + 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 1 The table shows some measurable quantities. Which row gives the correct order of magnitude of the measurable quantity in the stated unit? Measurable quantity Order of magnitude unit A mass of a coin 10−4 kg B thickness of a sheet of paper 10−2 m C weight of an apple 100 N D temperature of a person’s body 101 K 2 The frequency f of vibration of a mass m supported by a spring with spring constant k is given by the equation pqf Cm k= where C is a constant with no units. What are the values of p and q? p q A − 1 2 − 1 2 B − 1 2 1 2 C 1 2 − 1 2 D 1 2 1 2 © DHS 2021 9749/01

5 © DHS 2021 9749/01 [Turn over 3 P and R are coplanar vectors. If X = P – R, which diagram best represents vector X? A B C D 4 A mass of 5.0 kg is released from rest on a frictionless surface inclined at 30° to the horizontal. Air resistance is negligible. How far does the mass travel in a time of 0.80 s? A 1.6 m B 2.0 m C 2.7 m D 3.1 m

6 © DHS 2021 9749/01 [Turn over 5 A cannon fires a cannonball with an initial speed v at an angle α to the horizontal. Which equation is correct for the maximum height H reached? A sin 2 vH g α= B sin 2 gH v α= C ( ) 2 sin 2 vH g α= D 2 sin 2 gH v α= 6 The resultant force acting on an object is slowly increased. Which graph could show the variation with time t of the momentum p of the object? A B C D

7 © DHS 2021 9749/01 [Turn over 7 A box is shown resting on the ground. Newton’s third law of motion implies that four forces of equal magnitude are involved. These forces are labelled P, Q, R and S. Forces P and Q act on the box. Forces R and S act on the Earth. For clarity, the forces are shown slightly separated. Which statement about the forces is correct? A P is the equal and opposite force to Q and both are forces of contact. B Q is the equal and opposite force to P and both are gravitational forces. C R is the equal and opposite force to S and both are forces of contact. D S is the equal and opposite force to Q and both are gravitational forces. 8 A pipe, open at one end, floats in a liquid as shown. The cross-sectional area of the pipe is 0.012 m2. The weight of the pipe is 32 N. What is the density of the liquid? A 680 kg m−3 B 910 kg m−3 C 6700 kg m−3 D 8900 kg m−3

8 © DHS 2021 9749/01 [Turn over 9 The Achilles tendon in a rabbit’s leg is stretched when the rabbit jumps. The graph shows the variation with tension of the length of the tendon. What is the elastic potential energy in the tendon when the tension is 400 N? A 0.40 J B 0.80 J C 2.4 J D 7.4 J 10 The kinetic energy Ek of an object of mass m moving at speed v is given by the equation Ek = 1 2 mv2 Which equation is not used in the derivation of this equation? A F = ma B W = Fs C v 2 = u2 + 2as D s = vt 11 A combined heat and power (CHP) station generates electrical power and useful heat. The diagram shows the input and output powers for a CHP station. What is the efficiency of the CHP station for producing useful power? A 31% B 38% C 50% D 81%

9 © DHS 2021 9749/01 [Turn over 12 An object tied to the end of a light inextensible string of length 25 cm is swung in a vertical circle as shown. Determine the minimum speed of the object in order that the string remains straight throughout the motion. A 1.6 m s−1 B 2.2 m s−1 C 2.5 m s−1 D 3.1 m s−1 13 A stationary object of mass m is released at a point P on the line joining the centres of the two planets A and B. The gravitational potential at several points along the line joining the centres of the two planets are shown in the figure below. The object will accelerate towards one of the planets. What is the speed of the object just before it hits the surface of the planet? A 4.36 x 103 m s−1 B 5.18 x 103 m s−1 C 9.89 x 103 m s−1 D 1.08 x 104 m s−1 P Planet A Planet B gravitational potential / 106 J kg−1 −62.3 −13.4 −3.9 (not to scale) m 25 cm

10 © DHS 2021 9749/01 [Turn over 14 An Earth satellite is moved from one stable circular orbit to another stable circular orbit at a greater distance from the Earth. Which of the following correctly describes the energy of the satellite? 15 An ideal gas expands at constant temperature by absorbing heat Q. It then returns to its original volume without any heat exchange with the surrounding. The net change in internal energy of the gas as a result of the two processes is A zero. B smaller than Q. C equal to Q. D