RI 2023 Y5 H2 Phy Promo Sect A

© Raffles Institution 9749 RAFFLES INSTITUTION 2023 YEAR 5 PROMOTIONAL EXAMINATION 2 October 2023 Time: 2 hr 30 min H2 PHYSICS RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION FFLES Section A INSTRUCTIONS TO CANDIDATES There are 3 sections in this paper. Section A consists of 15 multiple-choice questions. For each question, four suggested answers are given. You are to choose the most appropriate one and shade your answer on the OMR form, using a soft pencil. You are advised to attempt Section A first. The OMR form will be collected at the end of the first 30 minutes. Section B consists of 5 structured questions. You are to write your answers in the spaces provided. Section C consists of 2 longer structured questions. You are to write your answers in the spaces provided. Attempt ALL the questions in Sections A, B and C. This document consists of 10 printed pages.

2 © Raffles Institution 9749 [Turn over Data speed of light in free space c = 3.00 × 108 m s−1 permeability of free space 0µ = 4π × 10−7 H m−1 permittivity of free space 0ε = 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 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 Formulae uniformly accelerated motion s = 21 2ut at+ 2v = 2 2u as+ work done on/by a gas W = pV∆ hydrostatic pressure p = ρgh gravitational potential φ = Gm r− temperature T/K = / C 273.15T °+ pressure of an ideal gas p = 21 3 Nm cV mean translational kinetic energy of an ideal gas molecule E = 3 2 kT displacement of particle in s.h.m. x = 0 sinxt ω velocity of particle in s.h.m. v = 0 cosvt ω 22 0xxω= ±− electric current I = Anvq resistors in series R = 12 RR++  resistors in parallel 1/R = 1211 RR++  electric potential V = 4 Q rε0π alternating current/voltage x = 0 sinxt ω magnetic flux density due to a long straight wire B = 0 2 d µ π I magnetic flux density due to a flat circular coil B = 0 2 N r µ I magnetic flux density due to a long solenoid B = 0nµ I radioactive decay x = ( )0 expxt λ− decay constant λ = 12ln2 t

3 © Raffles Institution 9749 [Turn over Section A (15 marks) 1 A spherical balloon is gradually inflated. Its diameter is measured at regular intervals and the uncertainty in the diameter is estimated. The volume of the balloon is then calculated at each interval using the diameter measured. Which graph shows how the fractional uncertainty in the volume of the balloon varies with the fractional uncertainty in the diameter of the balloon? 2 Which sequence shows the unit prefixes in order of decreasing magnitude? A kilo, giga, tera B deci, mega, kilo C centi, pico, nano D milli, micro, nano fractional uncertainty in volume fractional uncertainty in diameter 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 0.1 0.2 0.3 0.4 0.5 D C B A

4 © Raffles Institution 9749 [Turn over 3 A car of length 3.2 m accelerates uniformly from rest as a bus of length 12 m passes it s front at a constant speed of 112 m s− as shown. After 30 s, the car passes the front of the bus as shown. What is the acceleration of the car? A 20.80 m s− B 20.81 m s− C 20.83 m s− D 20.86 m s− 12 m 3.2 m starts to accelerate 12 m 3.2 m

5 © Raffles Institution 9749 [Turn over 4 A cart is placed on a horizontal track between a motion sensor and a force sensor. It is given a push such that it moves towards the force sensor and collides with it. The variation with time of the velocity of the cart and the force on the sensor during the collision as measured by the motion sensor and force sensor respectively, are shown in the graphs. What is the mass of the cart? A 3.4 kg B 4.6 kg C 6.9 kg D 24 kg motion sensor force sensor track cart velocity / time / s 0.1 0.2 0.3 0 −0.1 −0.2 0.02 0.04 0.06 0.08 0.10 0 time / s force / N 30 40 50 0 20 10 0.02 0.04 0.06 0.08 0.10 0

6 © Raffles Institution 9749 [Turn over 5 Which statement about upthrust is always correct? A The upthrust on an object is equal to the weight of the object. B Two objects of the same mass will experience the same upthrust when fully submerged in the same type of liquid. C The upthrust experienced by an object submerged in a liquid, is due to the fluid pressure at the bottom surface of the object. D A solid metal sphere and a hollow plastic sphere with the same dimensions will experience the same upthrust when fully submerged in the same type of liquid. 6 The diagram shows a light, right-angle L-shaped rod PQR. Side PQ is twice the length of side QR. The rod is pivoted at point O, the midpoint of side PQ , such that it rotates freely in the vertical plane. A small piece of clay of mass m is attached at R and another small piece of clay of mass 4m is attached at P. When the rod rests in equilibrium, PQ is at an angle θ to the vertical. What is the value of θ ? A 7.1° B 14.0° C 18.4° D 26.6° P Q R O

7 © Raffles Institution 9749 [Turn over 7 An electric crane is used to lift a container from the ground. The graph shows the variation with time of the total energy of the container. If the efficiency of the electric crane is 65 %, what is the maximum electrical power supplied to the crane during the 10 seconds? A 9.8 kW B 15 kW C 23 kW D 31 kW 8 The mean radius of the Earth’s orbit around the Sun is 111.50 10 m× . What is the mean speed of the Earth in its orbit around the Sun? A 711.09 10 m s −× B 412.99 10 m s −× C 315.95 10 m s−−× D 711.99 10 m s−−× total energy / kJ time / s 0 10 20 30 40 50 0 2 4 6 8 10

8 © Raffles Institution 9749 [Turn over 9 A small ball is