NJC_H1_PHY_P2_Question

1    NJC 2016  8866/02/16      NATIONAL JUNIOR COLLEGE PRELIMINARY EXAMINATIONS HIGHER 1 CANDIDATE NAME SUBJECT CLASS REGISTRATION NUMBER PHYSICS Paper 2 Structured Questions Candidates answer on the Question Paper. No Additional Materials are required. 8866/02 31 Aug 2016 2 hours READ THE INSTRUCTION FIRST Write your subject class, registration 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 a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. The use of an approved scientific calculator is expected where appropriate. Section A Answer all questions. Section B Answer any two questions. Please circle on the front page the questions you are submitting. You are advised to spend about one hour on each section. The number of marks is given in brackets [ ] at the end of each question or part question . For Examiner’s Use Section A (40 Marks) 1 2 3 4 5 Section B (40 Marks) 6 7 8 Total (80m) This document consists of 20 printed pages, including this cover page.

2    NJC 2016  8866/02/16      Formulae uniformly accelerated motion, s= u t + ½ a t2 v2 = u2+ 2as work done on/by a gas, W = pV hydrostatic pressure, p = gh resistors in series, R= R 1 + R2 + … resistors in parallel, 1/R = 1/R 1 + 1/R2 + … Data speed of light in free space, c = 3.00 x 108 m s-1 elementary charge, e = 1.60 x 10-19 C the Planck constant, h = 6.63 x 10-34 J s unified atomic mass constant, u = 1.66 x 10-27 kg rest mass of electron, me = 9.11 x 10-31 kg rest mass of proton, mp = 1.67 x 10-27 kg acceleration of free fall, g = 9.81 m s-2

3    NJC 2016  8866/02/16    Section A Answer all the questions in the spaces provided. 1 (a) (i) By reference to equations of motion, derive an expression for the kinetic energy, Ek, of an object of mass m moving at speed v. [2] (ii) It is often stated that many forms of transport transforms chemical energy into kinetic energy. Explain briefly why a cyclist travelling at constant speed is not making such transformation. ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………….………[2] (b) A car, of mass 720 kg, travelling along a horizontal road with a constant speed of 31 m s-1 would require a power of 36.6 kW. (i) Determine the work done in overcoming the external forces opposing the motion of the car during a time of 5.0 minutes. Work done = ……………………. J [2] (ii) Hence, with reference to (b)(i), suggest, with a reason, whether it would be worthwhile to develop a system whereby when the car slows down, its kinetic energy would be stored for re-use when the car speeds up again. ………………………………………………………………………………………… ………………………………