Physical Sciences Grade 12 P1 Western Cape Mock 2025 QP

Western Cape »/ Government METRO NORTH EDUCATION DISTRICT SCHOOL-BASED ASSESSMENT SEPTEMBER TRIAL COMMON EXAMINATION PHYSICAL SCIENCES P1 TASK NO.: 5 SEPTEMBER 2025 TOTAL: 150 DURATION: 3 hours This question paper consists of 19 pages and 3 data sheets

10. Wes 12. Write your name in the space below and submit the question paper with your answer sheets. NAME AND SURNAME: GRADE: 12 This question paper consists of TEN QUESTIONS. Answer ALL the questions on your ANSWER SHEETS. Start EACH question on a NEW page on your ANSWER SHEETS. Number the answers correctly according to the numbering system used in this question paper. Leave ONE line between two sub questions, for example between QUESTION 2.1 and QUESTION 2.2. You may use a non-programmable calculator. You may use appropriate mathematical instruments. You are advised to use the attached DATA SHEETS. Show ALL formulae and substitutions in ALL calculations. Round off your FINAL numerical answers to a minimum of TWO decimal places. Give brief motivations, discussions etc. where required. Write neatly and legibly.

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 numbers (1.1 to 1.10) on your ANSWER SHEETS, e.g. 1.11 E. dal 1.2 A horizontal force F is applied to a crate, causing it to move over a rough, horizontal surface as shown below. crate rs ~ The kinetic frictional force between the crate and the surface on which it is moving depends on ... A the applied force F. B the surface area of the crate in contact with the floor. Cc how quickly the crate moves along the surface. D the upward force exerted by the surface on the crate. (2) A person stands on a bathroom scale that is calibrated in newton, in a stationary elevator. The reading on the bathroom scale is w. The elevator now moves with a constant upward acceleration of 4 g, where g is the gravitational acceleration. What will the reading on the bathroom scale be now? A “ww B Yaw Cc w D Flaw (2)

1.3 1.4 1.5 1.6 A hot air ballon is moving upwards at a constant velocity v. A cellphone is dropped from the hot air balloon. What is the velocity of the cellphone at the instant it is dropped from the balloon? A v downwards. B v upwards. ie Zero. D =. 2v downwards. (2) Which one of the following best describes an inelastic collision? Neither kinetic energy nor momentum are conserved. Both momentum and kinetic energy are conserved. Kinetic energy is conserved but total linear momentum is not conserved. 0080 > Kinetic energy is not conserved but total linear momentum is conserved. (2) A 1000 W motor lifts a 100 kg mass to a height of 5 meters in 10 seconds at a constant speed. What is the power output of the motor in this situation? 490 W 500 W 1.000 W 5 000 W (2) 000 > An astronomer at SALT observes that the light spectrum of a star has been red shifted. How have the observed frequency of light from the star and the distance between the star and Earth changed? OBSERVED FREQUENCY DISTANCE BETWEEN OF LIGHT THE STAR AND EARTH A Increased Decreased B Decreased Increased Cc Increased Increased D Decreased Decreased (2)

1.7 1.8 Two point charges each having a charge of ? are placed ata distance, d meters apart. If the distance between them is doubled, by what factor does the force between them change? A B Cc D 2 4 VA Va (2) In the circuit diagram below, Rx and Ry are identical ohmic resistors connected in parallel. When the switch is open, the ammeter reading is 0,1 A and the voltmeter reading is 3 V. Ignore the internal resistance of the battery. © [Rx | @) Ry What will be the reading on the AMMETER and VOLTMETER when the switch is closed? READING ON AMMETER | READING ON VOLTMETER A_ | Equal to0,1A Equal to 3 V B_ | Greater than 0,1 A Equal to 3 V C | Less than0,1A Less than 3 V D_ | Greater than 0,1 A Greater than 3 V (2)

1.9 A group of leaners built an electric generator. They then used this generator to investigate how the magnitude of the induced emf would change as the magnetic field strength changed. Which ONE of the following is CORRECT regarding the variables for the investigation? DEPENDENT INDEPENDENT CONTROL VARIABLE VARIABLE VARIABLE A Magnetic field Number of turns of | Magnitude of strength coil of generator induced emf B Magnitude of Number of turns of | Magnetic field induced emf coil of generator strength Magnitude of Magnetic field Number of turns of ‘ induced emf strength coil of generator " Number of turns of | Magnitude of Magnetic field coil of generator induced emf strength 1.10 To see an absorption spectrum, dispersed light must ... A Have passed through a gas that is at the same temperature as the source of light. B Have passed through a gas that is substantially cooler than the source of light. Cc Have passed through a gas that is substantially hotter than the source of light. D Come straight out of a white-hot filament. (2) (2) [20]

The sketch below shows a 2 kg block on an incline with an angle of 40° and is attached to a 5 kg block on the ground by an inelastic rope. The coefficient of kinetic friction on the incline is 0,2. A force of 70 N is applied to the 5 kg block at the moment when the rope attached to the 5 kg block is at an angle of 20°, a kinetic frictional force of 17,15 N is measured for the 5 kg block. Fapplied =70N |» 2.1 State Newton’s second law of motion in words. (2) 2.2 Draw a free-body diagram showing ALL forces acting on the 5 kg block. (5) 2.3 Calculate the kinetic frictional force on the 2 kg block. (3) 2.4 Calculate the magnitude of the 5 kg block’s acceleration at the instant when the angle of the rope on the 5 kg block is 20°. (6) [16]

The position-time graph is given for a ball which is thrown down from a vertical height of 1,8 m. The ball bounces on reaching the ground. The contact time between the ball and the floor can be ignored. Ignore air resistance. Position (m) Time (s) 3.1 Define the term projectile. (2) 3.2 Calculate the initial speed at which the ball was thrown. (3) 3.3. Determine the velocity of the ball as it leaves the ground following the bounce. (3) 3.4 Calculate the value of time t. (4) 3.5 Sketch the velocity-time graph to represent the motion of the ball. Indicate the following on the graph: . The initial velocity at which the object was thrown. ° The velocity at which the ball bounces off the ground. . The time of the first ball bounce. (4) [16]

The diagram below shows two sections, XY and YZ, of a horizontal, flat surface. Section XY is frictionless, while section YZ is rough. A 5kg trolley, moving with a velocity of 4 m.s" to the right, collides head-on with a 2 kg trolley moving with a velocity of 1 m.s‘ towards the 5 kg trolley. After the collision, the two trolleys stick together and move to the right pass point Y. 4m.s* 1m.s" ——> ———— L J I r xX Y z 4.1. State the principle of conservation of linear momentum in words. (2) 4.2 Calculate the magnitude of the velocity of the combined trolleys at point Y. (4) The combined trolleys travel for 0,3 s from point Y before coming to a stop at point Z. 4.3 Calculate the magnitude of the net force acting on the combined trolleys while they move through section YZ. (4) [10]

5.1. Agymnast, with an unknown mass m, jumps vertically upwards from a trampoline as shown below. 5m 4,3 mi The gymnast loses contact with the trampoline at a height of 1,3 m above the ground and reaches a maximum height of 5 m above the ground. Ignore all effects of friction. 5.1.1 State the Jaw of conservation of mechanical energy in words. (2) 5.1.2 Use ENERGY PRINCIPLES to calculate the velocity with which the gymnast leaves the trampoline. (4) 5.1.3 If the effects of friction were NOT ignored, how would the maximum height reached be affected? Write only INCREASE, DECREASE or REMAIN THE SAME. Explain your answer. (2) 10

5.2 A toy train with a mass of 1,4kg is released from rest and moves along a track down an incline as shown below. It has a speed of 0,6 ms" at point P, which is at a vertical height of 1,5 m above the ground. The curved part of the track, PQ, is 1,8 m in length. The toy truck's speed at point Q is 3 m-s*. There is a constant frictional force acting on the toy truck from P to Q. Q 5.2.1 Is frictional force a conservative or non-conservative force? Explain your answer. (2) 5.2.2 Calculate the magnitude of the average frictional force experienced by the toy truck. (6) [16] 11

A car moves at a constant velocity along a straight, horizontal road towards a device which is capable of emitting and detecting sound waves. The device emits sound waves with a wavelength of 0,013 m. The sound waves are reflected off the surface of the car and the device detects sound waves with a frequency of 31 500 Hz. Assume that the speed of sound in air is 340 m.s*. 6.1 State the Doppler Effect in words. (2) 6.2 Determine the frequency of the emitted waves. (3) The speed limit on this road is 100 km.h™. 6.3. Determine if the vehicle was driving over the speed limit using an appropriate calculation. (6) [11] 12

7.1. Two identical charged metal spheres Qi and Qz are placed on insulated stands with their centres 40 cm apart. The charge on Q: is -3,8 nC. The electrostatic force of attraction between the two spheres is 8,54 x 1077 N. 40 cm | | t U Q Qz -3,8 nc l | 7.1.1 State Coloumb's faw in words. (2) 7.1.2 Calculate the charge on Qz. (3) 7.2 _Two-point charges, A and B, are placed 3 m apart. The charge on A is +6 x 10°C and the charge on B is -3 x 10° C. P is a point 4 m to the right of charge A. 4m ———_# we BP Pp ‘« 3 m > P 7.2.1 Define the term electric field at a point. (2) 7.2.2 Calculate the net electric field at point P. (4) 7.2.3. A proton is placed at point P. Calculate the magnitude of the initial acceleration of the proton if the mass of a proton is 1,67 x 10°” kg. (4) 7.2.4 If. an electron was placed at point P instead of a proton, how would the acceleration of the electron compare to that of the proton? Write only GREATER THAN, SMALLER THAN or EQUAL TO. (1) [16] 13

8.1 In diagram 1, when two NON-IDENTICAL resistors X and Y are connected in parallel across a6 V battery, the current through A1 is found to be 2 A. In diagram 2, when the two resistors are connected in series to a 6 V battery, Vz reads 4 V. The internal resistance of the battery and the resistance of the conducting wires may be ignored. Diagram 1 8.1.1 State Ohm's law in words. 8.1.2 Calculate the resistance of X and Y respectively. 14 Diagram 2 (2) (6)

8.2 Ancar battery has en emf of 12,6 V and an internal resistance of 0,08 Q. The two headlights have a total external resistance of 5,0 Q. The starter motor is connected in parallel with the headlights as shown in the diagram below. Assume the headlights are ohmic resistors. Starter motor 8.2.1 Write down the magnitude of the potential difference across switch S when both switches are open. (1) Switch P is now CLOSED but S is still OPEN. 8.2.2 Calculate the potential difference across the headlights when switch P is closed. (5) BOTH switches (P and S) are now CLOSED. 8.2.3 What will happen with the brightness of the headlights? Write down only INCREASE, DECREASE or REMAIN THE SAME. Explain your answer. (5) [19] 15

9.1 9.2 The diagram below shows the essential parts of a generator. [— carbon brush 20 & The coil rotates within the magnetic field. Write down the type of current (direct current (DC) or alternating current (AC)): 9.1.1 induced in the coil. (1) 9.1.2 passing through the 20 Q resistor. Give a reason for the answer. (2) An alternating current generator is used in the commercial generation of electricity. 9.2.1 State ONE fundamental difference in the design of an alternating current generator and the direct current generator. (2) 9.2.2 Fully explain why alternating current is preferred over direct current for the transmission of electricity over long distances. (2) 16

9.3 A A3 generator produces the following graph on emf versus time. 84,8 }--- +5 x il > | i) 7 “ > 005 0.10, 0,15 0,20, Time (s) 9.3.1 Write down the period for one revolution of the coil of the generator. (1) 9.3.2 Calculate the root mean square voltage (Vrms) for this generator. (2) 9.3.3 Calculate the resistance of a 40 W ohmic bulb connected to the generator. (3) [13] 17

The photocell below demonstrates an ultraviolet (UV) source of light shone onto a metal plate. The UV light with a wavelength of 284 nm ejects electrons from the surface of the metal plate with an average speed of 1,48 x 105 m.s™. UV Light Ee ca { |e Elscffons 10.1 Calculate the frequency of the UV light photons. (3) Some metals and their corresponding work functions are listed in the table below. Metal Work function (x107'9 J) Gold 7,8 Zinc 6,9 Calcium 4,3 Potassium 3,2 10.2 Define the term work function. (2) 10.3 By means of calculations, identify the metal that is used in this photocell from the table above. (5) 18

10.4 The metal as tried in Question 10.3 is now replaced with potassium. State how this change will influence the following. Choose from INCREASES, DECREASES or NO EFFECT. 10.4.1 10.4.2 10.4.3 the number of photoelectrons that will be ejected from the potassium metal surface. the ammeter reading. the kinetic energy of the photoelectrons. TOTAL: 150 MARKS 19 (1) (1) (1) [13]

GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 12 VRAESTEL 1 (FISIKA) TABLE 1: PHYSICAL CONSTANTS/ TABEL 1: FISIESE KONSTANTES NAME SYMBOL VALUE Acceleration due to gravity reB Swaartekragversnelling 9 ae me Universal gravitational constant G 6,67 x 10° N-m?-kg? Universele gravitasiekonstant Radius of Earth 6 Radius van die Aarde Re 6,38 x 10"m Mass of Earth 24 Massa van die Aarde Me 5.96% 1O"K6 Speed of light in a vacuum © ceil Spoed van lig in ‘n vacuum © oe a Eat Planck's constant 34). Planck se constant hn are We Coulomb's constant 9 N)-m2-C-2 Coulomb se konstant i 8.03 O Charge on electron . -19 Lading op electron & 16x10" Electron mass Ne 9,11 x 10°31 kg Electronmassa TABLE 2: FORMULAE/ TABEL 2: FORMULES MOTION/BEWEGING Ax = v{At +5adt? or/of Ay = v,At +5adt? vp? = v;7 + 2aAx or/of vp? = v;7 + 2ady i+ ax= (= 7 L)at or/of Ay= (- , “L) at 20

Fret = ma p=mv fr = nN fic = UN FneeAt = Ap = mvy — my; w=mg M M rf orlof F=G"X% g=G5 oof g=G5 WORK, ENERGY AND POWERI/ARBEID, ENERGIE EN DRYWING W = FAxcose U= mgh or/of Ep = mgh 1 K= > mv’ _ otlof Wnet = 4K orlof Whee = AE, E, = ; sp? AK = Ky —K; or/of AER = Exp — Eni Wrc = 4K +AU orlof Ww P=— Wie = JE, + AE, At Pave = FVave WAVES, SOUND AND LIGHT/GOLWE, KLANK EN LIG papa res =f. =F vetv, - — 4S f= yaa E= hf or E=h; E = Wo + Excmax) or E=Wo+Kmax where 1 1 E = hf and Wo=hfy and Exmaxy =ZMVnax OF Kmax = 5™MVinax E = Wo + Excmax) or E=W,+Kmax where E = hf and Wo=hfy and Exmax) = 5 MVinax or Kmax = 5 Mvinax 21

kQ Z r2 ae 72 WwW F V=— E=— q q or/of n= = |e ELECTRIC CIRCUITS/ELEKTRIESE STROOMBANE emf (€) =1(R + r) ee ee q = IAt RR, W=Vq w W =Vidt ~ At P=VI _ vat _v? = R I _ ‘max Pave = Vemslrms rms = 2 a Pave = Trask v2 Ves = ia Pave = 7 22