2024 DHS Promo Physics H2 Questions P2 final

1 © DHS 2024 9749/02 [Turn over Name: Index Number: Class: DUNMAN HIGH SCHOOL Promotional Examination Year 5 H2 PHYSICS Paper 2 Structured Questions Candidates answer on the Question Paper 9749/02 1 October 2024 1 hour 55 minutes READ THESE INSTRUCTIONS FIRST Write your class, index number and name at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the question paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Paper 1 MCQ 15 Paper 2 1 8 2 11 3 7 4 10 5 10 6 9 7 20 s.f. - 1 Total 90 This document consists of 19 printed pages and 1 blank page.

© DHS 2024 9749/01 [Turn over Data speed of light in free space c = 3.00 × 108 m s−1 permeability of free space o = 4 × 10−7 H m−1 permittivity of free space o = 8.85 × 10−12 F m−1 = (1/(36)) × 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

3 © DHS 2024 9749/02 [Turn over Formulae uniformly accelerated motion s ut at 21 2=+ v u as22 2=+ work done on / by a gas W p V= hydrostatic pressure p gh= gravitational potential Gm r =− temperature TT o/ K / C 273.15=+ pressure of an ideal gas Nmpc V 21 3=   mean translational kinetic energy of an E kT3 2= ideal gas molecule displacement of particle in s.h.m. x x t 0 sin= velocity of particle in s.h.m. v v t 0 cos= ( )xx22 0 = − electric current Anvq=I resistors in series R R R12 ...= + + resistors in parallel R R R 211 1 1 ...= + + electric potential QV r04= alternating current / voltage x x t 0 sin= magnetic flux density due to a long straight wire B d 0 2  = I magnetic flux denxity due to a flat circular coil 0 2 NB r = I magnetic flux density due to a long solenoid 0Bn = I radioactive decay ( )x x t 0 exp =− decay constant t 1 2 ln2 =

4 © DHS 2024 9749/01 Answer all the questions. 1 The rotational kinetic energy, RotationalE , and the moment of inertia, I, of a solid metal sphere are given by the following equations: 2 2 1 2 2 5 RotationalE MR = = I I where M is the mass of the solid metal sphere, R is the radius of that sphere and  is the angular velocity. Hence, the rotational kinetic energy, RotationalE , can be expressed as the following equation with the unit of Joules (J): 221 5 RotationalE MR = The details of the solid metal sphere are given in Table 1.1. An electronic balance, a micrometer screw gauge and an electronic stopwatch were used to obtain the data. Mass of sphere/ g 36.935 0.001 Diameter of sphere/ mm 20.79 0.01 Period of sphere/ s 1.2 0.2 Table 1.1 (a) State the base SI units of the moment of inertia, I. units of I = …………………………………. [1] (b) The base unit of  is given by s −1. Show that the rotational kinetic energy, RotationalE , shares the same base units with the translational kinetic energy given by 21 2 mv . [1]

5 © DHS 2024 9749/02 [Turn over (c) Calculate the value of RotationalE and its uncertainty. RotationalE = ………….…..…………….. ± ……………..………………. J [4] (d) State an example of a possible systematic and random error associated with the measurements to obtain RotationalE . systematic error: ……………………………………………………..……….……………... [1] random error: …..……………………………………………………………...….…………. [1] [Total: 8]

6 © DHS 2024 9749/02 2 An aeroplane is stationary on a runway. It begins to accelerate in a straight line along the runway and successfully takes off after 55.0 s. Fig. 2.1 shows the variation with time of the resultant force acting on the aeroplane while it is in contact with the runway. Fig. 2.1 (a) Suggest two reasons why the resultant force on the aeroplane varies rather than remaining constant as it accelerates along the runway. 1. ……………………………………………………………………………………………… ……………………………………………………………………………………………… 2. ……………………………………………………………………………………………… …………………………………………………………………..……………………… [2] (b) (i) State Newton’s second law of motion. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. …………………………………………………………………………………………… [1] resultant force / kN time / s 0 0 5.0 25.0 55.0 113 97

7 © DHS 2024 9749/02 [Turn over (ii) Calculate the momentum of the aeroplane at take-off. momentum = ………..…………..…..... N s [3] (c) The total mass of the aeroplane is 7.45 × 104 kg. Calculate the velocity vt of the aeroplane at take-off. velocity = …………………………….. m s−1 [1] (d) On Fig. 2.2, sketch a graph to show the variation with time of the velocity of the aeroplane as it travels along the runway. (Numerical values for the velocity are not required.) Fig. 2.2 [2] velocity / m s−1 time / s 0 0 5.0 25.0 55.0 vt

8 © DHS 2024 9749/02 (e) Estimate the distance travelled by the aeroplane along the runway. distance = ………..…………..…..... m [2] [Total: 11]

9 © DHS 2024 9749/02 [Turn over 3 A block of mass 0.20 kg has velocity 1.8 m s –1. It collides with a stationary block of mass 0.30 kg. The two blocks stick together after the impact. (a) Calculate the velocity of the two blocks after impact. Ignore the effects of friction. velocity = ................................................ m s−1 [2] (b) Show that the collision is inelastic. [2] (c) The collision took place over a time interval of 0.20 s. By calculating the change of momentum of each block, show how Newton’s third law of motion applies to this collision. [3] [Total: 7]

10 © DHS 2024 9749/02 4 (a) Explain what is meant by upthrust. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… ………………………………………………………………………………………………… [1] (b) Before a small balloon is inflated, its mass is 1.30 g as recorded on an electronic mass balance. The balloon is inflated with air so that it is spherical in shape with a diameter of 22.0 cm. (i) The density of air is 1.21 kg m−3. Calculate the mass of air displaced by the balloon. mass of air displaced = ……………….. g [2] (ii) The inflated balloon gives a reading of 1.55 g when placed on the balance. Calculate the mass of air in the balloon. mass of air in balloon = ………………… g [2] (iii) Suggest why the value in (b)(ii) is larger than the value in (b)(i). ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… …………………………………………………………………………………………… [1]