PHYSICAL SCIENCES P1 (PHYSICS)

Transcription

1 Physical Sciences P1 1 FS/September 014 Grade 1 Prep. Exam. PREPRTORY EXMINTION GRDE 1 PHYSIL SIENES P1 (PHYSIS) SEPTEMER 015 MRKS: 150 TIME: 3 HOURS This question paper consists of 13 pages and 3 data sheets.

2 Physical Sciences P1 FS/September 015 Grade 1 Prep. Exam. INSTRUTIONS ND INFORMTION 1. Write your name in the appropriate space on the NSWER OOK This question paper consists of TEN questions. nswer LL the questions in the NSWER OOK. egin EH question on a NEW page. 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 3.1 and QUESTION 3.. You may use a non-programmable calculator. You may use appropriate mathematical instruments. YOU RE DVISED TO USE THE TTHED DT SHEETS. 9. Show the formulae and substitutions in LL calculations. 10. Round off your final numerical answers to TWO decimal places. 11. Give brief motivations, discussions, et cetera where required. 1. Write neatly and legibly.

3 Physical Sciences P1 3 FS/September 015 Grade 1 Prep. Exam. QUESTION 1: MULTIPLE-HOIE QUESTIONS Four options are provided as possible answers to the following questions. Each question has only ONE correct answer. Write only the letter ( D) next to the question number ( ) in the NSWER OOK. 1.1 n object moving with a constant speed v has a kinetic energy E. Which one of the following will be true for the kinetic energy if the object has a constant velocity of v? D ½E E E 4E 1. sphere is attached to a string, which is suspended from a fixed horisontal bar as shown in the sketch. The reaction force to the gravitational force exerted by the earth on the sphere is D the force of the bar on the sphere. the force of the string on the sphere. the force of the sphere on the earth. the force of the bar on the string. () 1.3 ball is dropped from height h above the ground and reaches the ground with kinetic energy E. From which height must the ball be dropped to reach the ground with kinetic energy E? (Ignore all effects of friction.) D h 3h 4h 8h ()

4 Physical Sciences P1 4 FS/September 015 Grade 1 Prep. Exam. 1.4 The velocity versus time graph below represents the movement of an object under the influence of gravitational force. v v (m s -1 ) t 3t -v The displacement of the object in time 3t is D vt. zero. -vt. 3 v t. () 1.5 net force F accelerates two isolated objects, P and Q, from rest on a straight line for time t as shown below. Object P experiences an acceleration of a and object Q an acceleration of a. P F Q F If the amount of work done by net force F on object P equals W, the amount of work done on Q will be D W. ½ W. W. 4 W. ()

5 Physical Sciences P1 5 FS/September 015 Grade 1 Prep. Exam. 1.6 block, being pulled by a force F, and moving to the left on a rough horizontal surface, is slowing down. F The directions of the resultant force and the acceleration are DIRETION OF RESULTNT FORE DIRETION OF ELERTION to the right to the left to the right to the right to the left to the left D to the left to the right () 1.7 Three small identical spheres,, and is charged as shown in the diagram. The distance between sphere and is x. +16 µ -4 µ +4 µ For sphere to experience no resultant electrostatic force, the distance between and must be x D ¼ x. ½ x. x. 4 x. ()

6 Physical Sciences P1 6 FS/September 015 Grade 1 Prep. Exam. 1.8 Two metal balls and, mass m and m respectively, are allowed to roll down two different frictionless slopes as indicated in the diagram below. m m h h Ө Ө Which ONE of the following is true for the work done and the force acting on balls and respectively? MGNITUDE OF FORE WORK DONE F = F W W F F W W F F W W D F F W W () 1.9 In the circuits shown below all resistors and cells are identical. P V Q V Which ONE of the following gives the correct comparison between the voltmeter and ammeter readings in circuit P and Q. VOLTMETER REDING MMETER REDING V P V Q p Q V P V Q p Q V P V Q p = Q D V P = V Q p Q ()

7 Physical Sciences P1 7 FS/September 015 Grade 1 Prep. Exam In the circuit shown below the resistance of X is R and that of Y is R. X Y V If the power dissipated by X equals P, then the power dissipated by Y will be D ¼ P. ½ P. P. 4P. () TOTL SETION : 0 QUESTION (egin on a new page.) Two blocks of masses 5 kg and 3 kg respectively are connected by a light inextensible string that runs over a light frictionless pulley as shown in the diagram below. The 5 kg block experience a frictional force of 8 N and the coefficient of kinetic friction between the 3 kg block and the surface of the inclined plane is 0,15. 5 kg T 3 kg Define the term frictional force. (). Draw a labelled free-body diagram to indicate all the forces acting on the 3 kg block. (3).3 alculate the:.3.1 Magnitude of the frictional force acting between the 3 kg block and the surface of the inclined plane (3).3. Magnitude of the tension T in the string (6) [14]

8 Physical Sciences P1 8 FS/September 015 Grade 1 Prep. Exam. QUESTION 3 (egin on a new page.) all is thrown vertically downwards from the top of a building, 80 m high, at a velocity of 1 m s -1. t the same instant a second identical ball is thrown upwards at a velocity of 30 m s -1. all and ball pass each other after,135 s. Ignore all effects of air friction. 1 m s m 30 m.s Give the direction of the acceleration of ball while moving upwards. (1) 3. alculate the velocity of ball the moment it passes ball. (3) 3.3 alculate the distance between ball and,5 s after it was projected. (6) 3.4 Sketch a position-time graph for the motion of ball till it reaches the ground as well as for the motion of ball until it passes ball. Use the ground as zero position. learly indicate the time at which the balls pass each other. (3) [13] QUESTION 4 (egin on a new page.) trolley, mass 5 kg, moves at 4 m s -1 east across a frictionless horizontal surface. brick of mass 1,5 kg is dropped onto the trolley. 1,5 kg 5 kg 4 m s Define in words the Law of onservation of Momentum. () 4. State the condition for an elastic collision. (1) 4.3 alculate the change in momentum of the 5 kg trolley. (5) [8]

9 Physical Sciences P1 9 FS/September 015 Grade 1 Prep. Exam. QUESTION 5 (egin on a new page.) 5.1 boy on roller-skates moves at a constant velocity in an easterly direction along a frictionless horizontal part of a track carrying a parcel. He decides to increase his velocity by throwing the parcel horizontally away from him. X 4 m 6 m s -1 Ө In which direction must the parcel be thrown to cause a maximum increase in the velocity of the boy? (1) 5.1. Name and define in words the law in physics that you have applied in QUESTION (3) On reaching point at a velocity of 6 m s -1, the boy on the roller-skates, with total mass 57 kg, continues to move up a rough section of the track and comes to rest at position X, height 4m. The magnitude of the frictional force acting on the roller-skates, is 40 N alculate value Ө of the inclined plane. (6) 5. remote controlled car is driven up an inclined plane at 30 0 to the horizontal as shown below. The car of mass 4 kg, experiences an average forward force of 80 N. frictional force of 15 N is acting on the car as it moves up the plane. The speed of the car at the bottom of the inclined plane is 3 m s N 30 o 3 m s -1 Use energy principles to calculate the speed of the car after it has travelled 5 m up the inclined plane. (7) [17]

10 Physical Sciences P1 10 FS/September 015 Grade 1 Prep. Exam. QUESTION 6 (egin on a new page.) Light emitted from distant stars demonstrates the phenomenon known as red shift. 6.1 Explain how the phenomenon known as red shift can be used to explain an expanding universe. () 6. submarine can use the Doppler effect to detect the speed of ship. submarine at rest and just below the surface of the water, detects the frequency of a moving ship as 437 Hz, 0,985 times the actual frequency of the sound emitted by the ship. The speed of sound in water is 1470 m s Is the ship moving away from or towards the submarine? Give a reason for your answer. () 6.. alculate the speed of the ship. (5) 6.3 Name two applications of the Doppler effect in Medical Science. () [11] QUESTION 7 (egin on a new page.) The diagram below shows two identical insulated metal spheres. Spheres P an Q each carry a charge of 6 n. +6 n +6 n P 0 cm Q 7.1 Define oulomb s Law in words. () 7. Draw the electric field pattern due to the two spheres P and Q. (3) 7.3 alculate the magnitude of the electrostatic force between spheres P and Q. (4) third sphere, R, of charge - n is now placed at a position relative to the other spheres and a chosen point X as shown in the diagram below. +6 n +6 n - n P Q R X 0 cm 0 cm 10 cm 7.4 alculate the net electric field at point X due to spheres P, Q and R. (6) [15]

11 Physical Sciences P1 11 FS/September 015 Grade 1 Prep. Exam. QUESTION 8 (egin on a new page.) 8.1 The graph below is obtained from an experiment to calculate the internal resistance of a battery. I () Graph of current versus potential difference 0,6 0,4 0, 0 0,5 1,0 1,5,0,5 3,0 V(V) alculate V internal if the current in the circuit is equal to 0,. () 8.1. alculate the internal resistance of the battery. (4) 8. circuit is connected as shown below. When switch S 1 is closed, V external is equal to,5 V. The internal resistance of the battery is 0,8 Ω. emf = 4 V S 1 V 1 R 16 Ω 3 Ω S 8..1 Define Ohm s Law in words. () 8.. alculate the power dissipated by the 16 Ω resistor. (7)

12 Physical Sciences P1 1 FS/September 015 Grade 1 Prep. Exam alculate the resistance of R. (5) 8..4 Switch S is now closed. How will voltmeter reading V 1 be influenced? (Write down only INRESE, DERESE or STYS THE SME.) Give an explanation to your answer. (4) [4] QUESTION 9 (egin on a new page.) 9.1 The diagram below shows a coil that is rotated through a magnetic field. N S D Name the principle demonstrated in the above diagram? (1) 9.1. The maximum emf is generated at position of the rotation cycle. Give an explanation for this observation. () Name one structural difference between a D and generator. () Use the positions indicated in the diagram above and sketch a graph of current versus position for one complete rotation of a D generator. (Indicate the positions,, and D on the graph.) (4) 9. When an supply is connected to a lamp, it lights up with the same brightness as it does when connected to a 18 V battery (D source). The power dissipated by the lamp is equal to 60 W What is the rms voltage of the supply? (1) 9.. alculate the peak current delivered by the source. (5) [15]

13 Physical Sciences P1 13 FS/September 015 Grade 1 Prep. Exam. QUESTION 10 (egin on a new page.) The diagram below shows a circuit in which a photocell is irradiated alternately with red and blue light to demonstrate the photo-electric effect. Incident light e n ammeter reading is recorded when the photocell is irradiated with red light. Give an explanation for this observation. () 10. lue light with the same intensity as the red light is now used to irradiate the photocell. How will this influence the following: The kinetic energy of the photo-electrons (Write down only INRESE, DERESE or STYS THE SME.) (1) 10.. The ammeter reading. (Write down only INRESE, DERESE or STYS THE SME.) Give an explanation for your answer. (4) 10.3 The wavelength of the blue light used in the demonstration is 4,5 x 10-7 m. alculate the threshold frequency (cut-off frequency) of the metal used in the photo cell if the average speed of an emitted photo-electron is equal to 4,78 x 10 5 m s -1. (6) [13] TOTL SETION : GRND TOTL:

14 Physical Sciences P1 1 FS/September 015 Grade 1 Prep. Exam. DT FOR PHYSIL SIENES GRDE 1 PPER 1 (PHYSIS) GEGEWENS VIR FISIESE WETENSKPPE GRD 1 VRESTEL 1 (FISIK) TLE 1: PHYSIL ONSTNTS/TEL 1: FISIESE KONSTNTES NME/NM SYMOL/SIMOOL VLUE/WRDE cceleration due to gravity Swaartekragversnelling Universal gravitational constant Universele gravitasie konstante Speed of light in a vacuum Spoed van lig in 'n vakuum Planck's constant Planck se konstante oulomb's constant oulomb se konstante harge on electron Lading op elektron Electron mass Elektronmassa Mass of Earth Massa van arde Radius of Earth Radius van arde g 9,8 m s - G 6,67 x N m kg c 3,0 x 10 8 m s -1 h 6,63 x J s k 9,0 x N m e m e M R E -1,6 x ,11 x kg 5,98 x 10 4 kg 6,38 x 10 3 km

15 Physical Sciences P1 FS/September 014 Grade 1 Prep. Exam. TLE : FORMULE/TEL : FORMULES MOTION/EWEGING v v f f = v + a Δt i Δx Δy 1 = v iδt + aδt or/of 1 = v iδt + aδt v i + v f v i + v f = v i + aδx or/of v f = vi + aδy Δx = Δt or/of Δy = Δt FORE/KRG F net = ma p = mv f µ k k = N F Δt = Δp net Δp = mv f Gm m r mv i f s(maks ) µ s = N w = mg Gm r 1 F= g= WORK, ENERGY ND POWER/REID, ENERGIE EN DRYWING W = FΔxcos θ U= mgh or/of E P = mgh 1 1 W K = mv or/of E k = mv net = ΔK or/of Wnet = ΔEk Δ K = K f K i or/of Δ Ek = Ekf Eki W nc = K + U or/of W nc = E k + E p P = Fv P = W P = Δ t WVES, SOUND ND LIGHT/GOLWE, KLNK EN LIG av av / gemid Fv gemid v = f λ f v ± v v ± v L L L = f or/of s fl = fb v ± v s v ± vb 1 T = f E= hf E = h c λ E = W o + K max E = W o + E k where/waar or/of (max) 1 E = hf and/en W 0 = hf and/en or/of 0 (max) mv max... 1 K = mv Ek = (max) max

16 Physical Sciences P1 3 FS/September 014 Grade 1 Prep. Exam. ELETROSTTIS/ELEKTROSTTIK kq Q 1 F = r F E = q Q n = e or/of n = Q qe kq E = r W V = q ELETRI IRUITS/ELEKTRIESE STROOMNE V R = I Rs = R1 + R = R R R p 1 W = Vq W = VI Δ t W= I R Δ t W= V Δt R emf ( ε ) = I(R + r) q = I Δ t W P = Δt P = VI P = I R V P = R LTERNTING URRENT/WISSELSTROOM Imax I rms = / Vmax Vrms = / I I = V wgk wgk = maks V maks P P average = V rms Irms / Pgemiddeld = V wgk I wgk average I rms = R / P = R Vrms Paverage = / R P gemiddeld I wgk gemiddeld = V wgk R