2024 JPJC H1 Prelim P2

[Turn over Data READ THESE INSTRUCTIONS FIRST Write your name, class and index number in the spaces at the top of this page. 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 Answer all questions. Section B Answer any one question. 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. This document consists of 25 printed pages and 3 blank pages. JURONG PIONEER JUNIOR COLLEGE JC2 Preliminary Examination 2024 PHYSICS 8867/02 Higher 1 27 August 2024 Paper 2 Structured Questions 2 hours Candidates answer on the Question Paper. No Additional Materials are required. Name: _______________________________ Class: ______________ For Examiner’s Use Section A 1 / 5 2 / 7 3 / 12 4 / 8 5 / 13 6 / 15 Section B 7 / 20 8 / 20 Total / 80

2 2024/JPJC/Prelim/8867/02 Data speed of light in free space 81000.3 c m s–1 elementary charge 191060.1 e C unified atomic mass constant 271066.1 u kg rest mass of electron 311011.9 em kg rest mass of proton 271067.1 pm kg the Avogadro constant 231002.6 AN mol–1 gravitational constant 111067.6 G N m2kg–2 acceleration of free fall 81.9g m s–2 Formulae uniformly accelerated motion 2 2 1atuts  asuv 222  resistors in series ...21  RRR resistors in parallel .../1/1/1 21  RRR

3 2024/JPJC/Prelim/8867/02 [Turn over Answer all the questions in the spaces provided. 1 (a) All bodies radiate energy. The power P radiated by a body is given by  4P kAT where T is the thermodynamic temperature of the body, A is the surface area of the body and k is a constant. Determine the SI base units of k. SI base units ........................................ [2] (b) The maximum useful output power P of a car travelling on a horizontal road is given by 3P v b where v is the maximum speed of the car and b is a constant. For the car, 84 kW 5%P   and 0.56 7%b   in SI units. Determine the absolute uncertainty in the value of v. absolute uncertainty = ........................................ m s−1 [3]

4 2024/JPJC/Prelim/8867/02 2 A golf ball is chipped at an angle of θ above the horizontal and strikes the level ground 1.5 s later, reaching a horizontal distance of 15 m. Air resistance negligible. Take g to be 10 m s2. (a) Calculate the vertical component of the initial velocity. vertical component of initial velocity = ………………............... m s1 [2] (b) Using your answer to (a), or otherwise, draw on Fig. 2.1 the variations with time t of the horizontal displacement sh, the horizontal component of the velocity vh and the vertical component of the velocity vv of the ball until it strikes the ground. Add a suitable scale to each vertical axis. Take the upward direction as positive.

5 2024/JPJC/Prelim/8867/02 [Turn over Fig. 2.1 [5] sh / m vh / m s1 vv / m s1 1.5 t / s 1.5 t / s 1.5 t / s

6 2024/JPJC/Prelim/8867/02 3 (a) State Newton’s second law of motion. ………………………………………………………………………………………………….. ……………………………………………………………………………………………… [1] (b) Define impulse. ………………………………………………………………………………………………….. ……………………………………………………………………………………………… [1] (c) Fig. 3.1 shows a model of a system being designed to move concrete building blocks from an upper to a lower level. Fig. 3.1 The model consists of two identical trolleys of mass M on a ramp which is at 35° to the horizontal. The trolleys are connected by a wire that passes around a pulley of negligible mass at the top of the smooth ramp. Two concrete blocks each of mass m are loaded onto trolley A at the top of the ramp. The trolley is released and accelerates to the bottom of the ramp where it is stopped by a flexible buffer. The blocks are unloaded from trolley A and two blocks are loaded onto trolley B that is now at the top of the ramp. The trolleys are released and the process is repeated. Assume that no friction acts at the axle of the pulley and air resistance is negligible. trolley B trolley A

7 2024/JPJC/Prelim/8867/02 [Turn over Fig. 3.2 shows the side view of trolley A loaded with two concrete blocks when it is moving down the ramp. Fig. 3.2 (i) The tension in the wire when the trolleys are moving is T. Draw arrows on Fig. 3.2 to represent the magnitudes and directions of any forces and components of forces that act on the loaded trolley A parallel to the ramp as it travels down the ramp. Label the arrows. [2] (ii) Show that the acceleration a of trolley A along the ramp is given by sin35 .mga M m   [3] 35°

8 2024/JPJC/Prelim/8867/02 (iii) In practice, for safety reasons there is a friction brake in the pulley that provides a resistive force to reduce the acceleration to 25 % of the maximum possible acceleration. The distance travelled for each journey down the ramp is 9.0 m. The following data apply to the arrangement. Mass of a trolley M = 95 kg Mass of a concrete block m = 30 kg Calculate the time taken for a loaded trolley to travel down the ramp with this reduced acceleration. time = ........................................ s [3] (iv) Discuss how the flexible buffer ensures minimal damage to each trolley when it is stopped by the buffer. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ............................................................................................................................ [2]

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10 2024/JPJC/Prelim/8867/02 4 Fig. 4.1 shows a 60.0 kg painter on a uniform scaffold of mass 25.0 kg and length 6.0 m, supported from above by ropes. A 4.0 kg pail of paint is placed 1.0 m away from one of the supports. Fig. 4.1 (a) On Fig. 4.2, draw and label the forces acting on the scaffold. Fig. 4.2 [2] 1.0 m 1.0 m 4.0 m A B scaffold 1.0 m x ropes 1.0 m 1.0 m 4.0 m A B scaffold paint