Physical Sciences Grade 12 P1 Free StateNovember 2014 QP

education Department of Education FREE STATE PROVINCE PREPARATORY EXAMINATION GRADE 12 PHYSICAL SCIENCES P14 (PHYSICS) SEPTEMBER 2014 MARKS: 150 TIME: 3 HOURS This question paper consists of 14 Pages and 3 data sheets. Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P14 2 FS/September 2014 Grade 12 Prep.Exam. INSTRUCTIONS AND INFORMATION 1. 2 3 4. 5 @ 10. 11. 12. Write your name in the appropriate space on the ANSWER BOOK. Answer ALL the questions in the ANSWER BOOK. You may use a non-programmable calculator. You may use appropriate mathematical instruments. Number the answers correctly according to the numbering system used in this question paper. YOU ARE ADVISED TO USE THE ATTACHED DATA SHEETS. Give brief motivations, discussions, et cetera where required. Round off your final numerical answers to TWO decimal places. Begin EACH question on a NEW page. Leave ONE line between two sub-questions, for example between QUESTION 3.1 and QUESTION 3.2. Show the formulae and substitutions in ALL calculations. Write neatly and legibly. Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 3 FS/September 2014 Grade 12 Prep.Exam. QUESTION 1: MULTIPLE-CHOICE QUESTIONS Four options are provided as possible answers to the following questions. Each question has only ONE correct answer. Write only the letter (A — D) next to the question number (1.1 — 1.10) in the ANSWER BOOK. 1.1 The impulse acting on an object is equal to the ... A product of the mass and the velocity of the object. B acceleration of the object. C change in momentum of the object. D rate of change in momentum of the object. (2) 1.2 Which ONE of the following phenomena is evidence for the particle nature of light? A __ Diffraction B Red shift C Interference D_-Photo-electric effect (2) 1.3 Which one of the following graphs best represents the relationship between the magnitude of the electric field (E) and the charge (Q) at a distance r from the charge? A gf B E+ \______. -_—_, Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 4 FS/September 2014 Grade 12 Prep.Exam. 1.4 Anet force F acts on each of two isolated objects, P and Q, as shown below. The mass of Q is three times that of P. (Ignore the effects of friction.) Q P F F 3m +¥——> neo If the rate of change of momentum of object Q is x, then the rate of change of momentum of object P is as follows: 4, A 3 4, B 3 Cc x D 3x (2) 1.5 The velocity-time graph below represents the vertical motion of an object. Velocity (m-s"') > xX Time (s) Which ONE of the following correctly describes the displacement Ay and acceleration of the object at point X indicated on the graph? Displacement Acceleration A Zero -9,8 B Ay zero Cc Ay 9,8 D -A\ 9,8 ¥ (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P14 5 FS/September 2014 Grade 12 Prep.Exam. 1.6 Two objects, m; and mz, a distance r apart, experience a gravitational force F. The mass of m, is now doubled and the distance r is halved. The gravitational force between m, and mz will now be ... a A . ah 1 B =F 2, CF. Ds s8F. (2) 1.7 Which ONE of the following equations represents the principle of the conservation of mechanical energy? A AE. = AE, B AE, =- AE, CAE. + AE, —Wpyc = 0 D AE, — AE, = Wre (2) 1.8 — A block moves at a constant velocity across a horizontal surface while experiencing a frictional force f,. If the same block moves across the same surface up a slope, the following statement will be correct: A fk(slope) > f,(horizontal) B_ fk(slope) < (horizontal) C_ f(slope) = f,(horizontal) D — f(slope) = f,(horizontal) and bx(slope) = 1,(horizontal) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 6 FS/September 2014 Grade 12 Prep.Exam. 1.9 In which ONE of the circuits will the reading on the voltmeter be the smallest? (The cells and resistors are identical in each circuit.) (2) 1.10 In circuit A and B shown below all resistors and cells are identical. A >= If the power dissipated by X equals P, then the power dissipated by Y will be... A %P. BP. Cc 2p. D 4P. (2) TOTAL SECTION A: 20 Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 7 FS/September 2014 Grade 12 Prep.Exam. QUESTION 2 (Begin on a new page.) A cricket ball is hit vertically upwards at 30 m-s~' from the ground. After 4 s it strikes a bird flying by. The cricket ball then strikes the ground at 27 m-s~'. It bounces off the ground at a velocity of 24 m-s”' as illustrated below. Ignore the effects of friction. vk b—?> - ------------ 2 — 30ms* !! 24ms7 27 ms" 2.1 Calculate: 2.1.1 The time to reach the maximum height after it is hit upwards (3) 2.1.2 The height at which the cricket ball strikes the bird (4) 2.2 Sketch a position-time graph to represent the motion of the ball from the moment it is projected from the GROUND until it strikes the BIRD. Indicate the time t at which the ball strikes the bird. USE THE GROUND AS THE ZERO POSITION. (2) 2.3 Calculate the displacement of the cricket ball from the moment it strikes the bird till it reaches its maximum height after bouncing off the ground. (5) 2.4 Is the collision of the cricket ball with the ground ELASTIC or INELASTIC? Explain your answer. (3) [17] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 8 FS/September 2014 Grade 12 Prep.Exam. QUESTION 3 (Begin on a new page.) The diagram below shows a spaceship, mass 3 500 kg, travelling in the vacuum in space in an orbit around the earth at a constant speed. 3.1 Name and define in words the law in Physics that explains the continuous orbiting of the spaceship around the earth at a constant speed in the vacuum of space. (3) 3.2 The spaceship is orbiting in a closed system. Explain in words the meaning of this statement. (2) The rocket engines are now ignited and exert a force of 12 000 N for 30 s on the spaceship to redirect and accelerate it back to earth. 3.3 Calculate the change in the velocity of the spaceship. (3) The spaceship, with the rocket engines switched off, strikes the earth’s atmosphere vertically at a speed of 800 m-s"' and decelerates to a speed of 100 m-s" within 20 s before it lands in the sea. 3.4 Draw a labelled free body diagram to indicate all the forces acting on the spaceship when it enters the earth’s atmosphere vertically. (2) 3.5 Calculate the magnitude of the average frictional force acting on the Spaceship when it moves through the earth’s atmosphere. (5) [15] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 9 FS/September 2014 Grade 12 Prep.Exam. QUESTION 4 (Begin on a new page.) The diagram below shows a truck of mass 1500 kg, and a broken down car of mass 500 kg, connected with a towing rod. The coefficient of static friction is 0,35 and the Coefficient of kinetic friction 0,2 for both the car and the truck. N 4.1 Define Newton's second law of motion. (3) 4.2 Calculate the magnitude of the minimum force needed to get the car to start moving. (3) The engine of the truck exerts a force of 10 000 N on the truck causing the truck-car system to experience a constant acceleration of 3,04 ms, 4.3 Draw a labelled free-body diagram showing ALL the HORIZONTAL forces acting on the truck. (3) 44 Calculate the magnitude of the force (T) in the towing rod. (5) [14] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 10 FS/September 2014 Grade 12 Prep.Exam. QUESTION 5 (Begin on a new Page.) A 3 kg metal block moves from rest at point A down an incline as shown in the diagram below and reaches a speed of 6 m-s” at B. Section AB of the path is frictionless. 5.1 Would you describe the movement of the block on section AB of the path as free fall? Give a reason for your answer. (2) 5.2 Calculate the net work done on the block as it moves down section AB of the path. (3) 5.3 Calculate the height of the block at position B. (4) 5.4 On reaching point B, the block continues to move down section BC of the path which is 5 m in length. The block now experiences a frictional force and reaches point C at a speed of 2 m-s™. Use the principle of the conservation of energy to calculate the magnitude of the frictional force acting on the block as it moves down section BC of the path. (5) [14] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 11 FS/September 2014 Grade 12 Prep.Exam. QUESTION 6 (Begin on a new page.) Light emitted from distant stars demonstrates the phenomenon known as red shift. 6.1 Briefly describe what is meant by the red shift in light emitted from distant stars. (2) 6.2 A line in the hydrogen absorption spectrum has a frequency of 3,6 x 10" Hz when measured in a laboratory. The same line in the absorption spectrum of a distant star has a frequency of 3,4 x 10'* Hz. Is the star moving away from or coming towards the earth? Give a reason for your answer. (2) 6.3 A racing car, with its headlights on, is approaching a spectator standing next to a track, at a constant speed of 280 km-h"’. The engine produces sound of frequency 1200 Hz. 6.3.1 Briefly explain why there is no observed colour change in the light from the headlights of the racing car while approaching a spectator. (2) 6.3.2 Calculate the frequency of the sound as heard by the spectator. (4) [10] QUESTION 7 (Begin on a new Page.) In the diagram below, point charge X has a charge of -12 nC. A is a point 30 cm from point charge X. xX 30cm A -12 nC 7.4 Define an electric field at a point in space. (2) 7.2 Calculate the magnitude of the electric field at point A due to point charge X. (3) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P14 12 FS/September 2014 Grade 12 Prep.Exam. A second point charge Y, carrying a charge of 8 nC, is now placed at position A and a third point charge Z, carrying a charge of 10 nC, is placed at a distance of 40 cm from Y as shown below. 30cm x -12 nc 8nc 40 cm Fa 10 nc 7.3 Draw a vector diagram to indicate the electrostatic forces exerted by point charges X and Z on point charge Y. (2) 7.4 If the magnitude of the electrostatic force exerted by point charge X on point charge Y equals 9,6 x 10° N, calculate the net electrostatic force exerted by point charges X and Z on point charge Y. (6) [13] QUESTION 8 (Begin on a new page.) In the circuit diagram below, resistors are connected in parallel as well as in series. The battery has an emf of 24 V and an internal resistance of 1,0 Q. When switch S; is closed the reading on V; is 21,0 V. 1 1 Ss; i | 40 2Q LL 8.1 Explain, in words, the meaning of a potential difference of 21 V. (2) 8.2 Calculate the: 8.2.1 Reading on voltmeter V2 (4) 8.2.2 Power dissipated by resistor R (8) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 13 FS/September 2014 Grade 12 Prep.Exam 8.3 Switch S2 is now closed. How will the power dissipated by the 3 O resistor be affected? (Write down only INCREASE, DECREASE or STAYS THE SAME). Explain the answer. (4) [18] QUESTION 9 (Begin on a new page.) 9.1 The diagram below demonstrates the principle for the generation of electricity. Four positions of the coil, A, B, C and D are shown. 9.1.1 On what principle does a generator work? (1) 9.1.2 Is the magnetic flux passing through the coil at position C a MAXIMUM or a MINIMUM? (1) 9.1.3 At which position of the coil’s rotation cycle will the maximum emf be induced? (Write only A, B or C.) Give an explanation to your answer. (3) 9.1.4 Sketch a graph of emf versus position of the coil for a clockwise rotation from A to D. Indicate the positions A, B, C and D on the graph. (4) 9.2 The graph below shows the power delivered by an AC source versus time. The peak/maximum voltage generated by the AC source is 80V. 300 t 150 Power (W) Time (s) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P1 14 FS/September 2014 Grade 12 Prep. Exam. 9.2.1 Name ONE advantage of alternating current. (1) Calculate: 9.2.2 The rms current induced by the AC source (5) 9.2.3 The frequency delivered by the AC source (3) {18} QUESTION 10 (Begin on a new Page.) 10.1 A blue light filter is placed in front of a hydrogen discharge tube and the blue light is shone onto a photocell. An ammeter reading is recorded. Incident light from discharge tube — 1 | | =0- 10.1.1 What type of spectrum is Produced by the hydrogen discharge tube? (1) 10.1.2 Name one apparatus that you will need to make the spectrum produced by the hydrogen discharge tube visible to the human eye. (1) 10.2 The blue filter is removed and replaced by a red light filter. No ammeter reading is recorded. Explain this observation. (2) 10.3 The cut-off (threshold) frequency of the metal used in the photo cell is 1,1 x 10"5Hz. The discharge tube is removed and the photo cell is radiated with green light of wavelength 450 nm. 10.3.1 Define the cut-off frequency of a metal. (2) 10.3.2 Will you observe an ammeter reading? Show all necessary calculations to indicate how you have arrived at the answer. (5) [11] TOTAL SECTION B: 130 GRAND TOTAL: 150 Copyright reserved

Downloaded from hlayiso.com Physical Sciences P1 1 FS/September 2014 Grade 12 Prep.Exam. DATA FOR PHYSICAL SCIENCES GRADE 12 PAPER 1 (PHYSICS) GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 12 VRAESTEL 1 (FISIKA) TABLE 1: PHYSICAL CONSTANTSI/TABEL 1: FISIESE KONSTANTES NAME/NAAM SYMBOL/S/MBOOL VALUE/WAARDE Swaarleleegvorsnetbg ce) 9,8 m-s? ramen keen e -1,6x 10°C Copyright reserved

Downloaded from hlayiso.com Physical Sciences P1 Grade 12 Prep.Exam. 2 TABLE 2: FORMULAE/TABEL 2: FORMULES MOTION/IBEWEGING VA =VjtaAdt Ax =v At+ Jadt? orlof Ay =v,At+taat? vty Vv, +V V,’ =v," +2aAx orlof v,? =v,? + 2ady ax-( a orlof ay=(“ eat FORCE/KRAG Fret =ma p=mv F,,At = "At =Ap oa Ap =mv, —mvy, f= om, Sm r? WORK, ENERGY AND POWERI/ARBEID, ENERGIE EN DRYWING W=FAxcos@ U=mgh oof E,=mgh K=5mv? oof = E, =p mv? Woa = AK onfof Wag = AE AK=K,-K, of/of AE, =E, -E, Whe = AK + AU or/of Whe = AE, + AE, Pave = FV ave pW At WAVES, SOUND AND LIGHTIGOLWE, KLANK EN LIG 1 v=fa Ta- f E=hf _ Viv, _ Vv, czars f, or/of a f, E=no x E=W, +Knex orfof E=WotEnm where/waar E=hf and/en W, =hf, and/en Ex =5m max... OF — Kaasy = MV ae Copyright reserved FS/September 2014

Downloaded from hlayiso.com Physical Sciences P1 3 FS/September 2014 Grade 12 Prep.Exam. ELECTROSTATICS/ELEKTROSTATIKA CIC? = _KQ r r ane, vi q q Q n=— = © orlof qe R=” emf (€)=I(R +1) I R, =R, +R + 1°1¢°1 q=I At R, R, R, Ne p-W. At W=VIAt W= FRat ie V7At peas j= VAL v2 W: R ae ALTERNATING CURRENT/WISSELSTROOM I I a Pavereae =Vimel| ms. / Premiddeld = Vrorl wok Tins =e 1 T yak = —maks_ 2 2 2) ean pie ae V, V, Von = — max / Vv = —Mmaks 2 v2 Is V2 wok V2 Parerage = vi / Premadeid = = Copyright reserved