final qp - physical science p1 physics - nov...

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This question paper consists of 16 pages, a data sheet of 3 pages, a 1-page answer sheet and 2 pages with graph paper.

PHYSICAL SCIENCES P1 (PHYSICS)

NOVEMBER 2007

NATIONAL SENIOR CERTIFICATE

GRADE 11

Physical Sciences/P1 (Physics) DoE/November 2007 NSC


2

INSTRUCTIONS AND INFORMATION 1. 2. 3. 4. 5. 6. 7. 8. 9.

Write your name and/or examination number (and centre number if applicable) in the appropriate spaces on the ANSWER BOOK, ANSWER SHEET and GRAPH PAPER provided. Answer ALL the questions. Answer SECTION A on the attached ANSWER SHEET. Answer SECTION B in the ANSWER BOOK provided, EXCEPT for QUESTIONS 6.2, 6.4 and QUESTION 8.3, which must be answered on the attached GRAPH PAPER. Non-programmable calculators may be used. Appropriate mathematical instruments may be used. Number the answers correctly according to the numbering system used in this question paper. A data sheet is attached for your use. Give brief motivations, discussions, et cetera if required.



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SECTION A Answer this section on the attached ANSWER SHEET. QUESTION 1: ONE-WORD ITEMS Give ONE word/term for EACH of the following descriptions. Write only the correct word/term next to the question number (1.1 – 1.5) on the attached answer sheet.

1.1 1.2 1.3 1.4 1.5

The rate of change of velocity The product of the perpendicular component of the force ( ⊥F ) and the distance from the point of action to the fulcrum A wave in which the particles are disturbed parallel to the direction of propagation of the wave The law that states that the induced emf in a conductor is equal to the rate of change of the magnetic flux linked with the conductor The theory which explains electrical conduction in semi-conductors

(1) (1) (1) (1) (1) [5]

QUESTION 2: MATCHING ITEMS Choose an item from COLUMN B that matches a description in COLUMN A. Write only the letter (A – I) next to the question number (2.1 – 2.5) on the attached answer sheet.

COLUMN A COLUMN B

2.1 2.2 2.3 2.4 2.5

Ratio of load to effort Whole number multiples of the fundamental frequency Always produces a virtual and diminished image Region of space in which an electric charge experiences a force Series connection of resistors in an electric circuit

A

B

C

D

E

F

G

H I

efficiency of a force convex lens overtones mechanical advantage concave lens harmonics electric field potential divider current divider

[5]



4

QUESTION 3: TRUE OR FALSE Indicate whether the following statements are TRUE or FALSE. Write only 'true' or 'false' next to the question number (3.1 – 3.5) on the attached answer sheet. If the statement is FALSE, write down the CORRECT statement.

3.1 3.2 3.3 3.4 3.5

Newton's law of universal gravitation states that 'the force of attraction between any two particles is directly proportional to the product of their masses and inversely proportional to the distance between them'. The speed of sound in a medium is determined by the type of medium and not by the frequency of the source. The wavelength of a longitudinal wave can be given as the distance between any two consecutive compressions. A beam of electrons moving parallel to a magnetic field experiences a maximum force. In metal conductors the resistance increases with an increase in temperature whereas in semiconductors the resistance decreases with an increase in temperature.

(2) (2) (2) (2) (2) [10]



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QUESTION 4: MULTIPLE-CHOICE QUESTIONS Four possible options are provided as answers to the following questions. Each question has only ONE correct answer. Choose the correct answer and make a cross (X) over the letter (A – D) next to the relevant question number (4.1 – 4.5) on the attached answer sheet.

4.1 A boy applies a force, F, to a crate as shown below. The crate moves at

constant velocity, v.

The crate is then turned on its end, reducing the surface area in contact

with the floor by half. In this new orientation, he pushes the crate across the floor with the same constant velocity.

The force he now applies is ...

A B C D

21 F

F 2F 4F

(3)

4.2 A person suffers from short-sightedness (myopia). Which ONE of the

following is TRUE about the eye lens and the position of the image?

EYE LENS POSITION OF IMAGE A Too round Behind the retina

B Too flat Behind the retina C Too round In front of the retina D Too flat In front of the retina

(3)

v

v



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4.3 Two spheres, S and T, on insulated stands, carry charges of +4µC and

-2µC respectively and are a distance r apart. The force that sphere S exerts on sphere T is F.

Sphere T is now moved to a distance 2r from sphere S.

What is the force that sphere S will now exert on sphere T?

A

B C D

41 F

21 F

2F 4F

(3) 4.4 In the circuit below, three bulbs are connected in series with a battery. Which ONE of the following switches should be closed to make bulb L glow

the brightest?

A

B C D

S1 only S2 only S3 only S1 and S2

(3)

S T +4μC -2μC

r

S3 S2

S1

L



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4.5 Semi-conductors conduct current by the movement of ... A

B C D

positive ions. negative ions. delocalised electrons. holes and electrons.

(3) [15]

TOTAL SECTION A: 35



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SECTION B INSTRUCTIONS AND INFORMATION 1. 2. 3.

Answer SECTION B in the ANSWER BOOK provided, EXCEPT for QUESTIONS 6.2, 6.4 and QUESTION 8.3, which must be answered on the attached GRAPH PAPER. The formulae and substitutions must be shown in ALL calculations. Round off your answers to TWO decimal places.

QUESTION 5 A bullet of mass 2 g is fired horizontally into a stationary wooden block of mass 1 kg. The bullet strikes the wooden block at a velocity of 490 m·s-1. The impact causes the block-bullet system to slide a distance of 20 cm from its original position before coming to rest. Assume the block experiences a constant frictional force.

5.1 5.2 5.3 5.4

Name and state the law, in words, that can be used to calculate the velocity of the block-bullet system immediately after impact. Calculate the magnitude of the velocity of the block-bullet system immediately after impact. Draw a free-body diagram of the block-bullet system. Show and label ALL the forces acting on the block-bullet system while it is moving. Assume, while the block-bullet system is moving, it experiences a constant acceleration of –2,4 m·s-2. Calculate the coefficient of kinetic friction between the wooden block and the surface.

(3) (5) (3) (5) [16]

20 cm

490 m·s-1 1 kg

2 g



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QUESTION 6 Overloading of motor vehicles is one of the many causes of road accidents on our country's roads. A Physical Sciences class investigated the relationship between force, mass, acceleration, stopping distance and stopping time. Different groups investigated different relationships. One group of learners did the investigation below. These learners used the following apparatus in their investigation: • Four trolleys • A ticker timer • Four lengths of ticker tape • A ramp (Runway) • A non-elastic string • A pulley • A 250 g mass piece They set up the apparatus as shown below:

The runway was inclined to compensate for friction. The mass piece accelerated the trolley down the incline. The incline was kept constant for the duration of the experiment. The mass was increased by stacking the trolleys one on top of the other after each reading. After analysis of the four ticker tapes, the following results were recorded:

FORCE

(N) MASS

(Trolley-units) ACCELERATION

(m·s-2) MASS1

2,5 1 4,4 2,5 2 2,8 2,5 3 2,3 2,5 4 1,9

250 g

Trolley

Ticker timer

Ticker tape



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6.1 Formulate an investigative question for this investigation. (2) 6.2 6.3 6.4 6.5

Complete the table on the attached GRAPH PAPER. Draw a graph of the dependent variable on the y-axis versus the independent variable on the x-axis. Indicate the following on your graph:

• Suitable heading • Labels for the axes • Appropriate scale • The four plotted points

Draw a straight line through the LAST THREE points. Draw a conclusion from the graph. Extrapolate (Extend) the line on the graph. Give a possible reason why the first point does NOT lie on the line. Use your conclusion in QUESTION 6.3 to explain to motorists why over-loading is dangerous.

(6) (2) (2) (3) [15]

QUESTION 7 Your study group wants to determine the weight of a friend. You have a 3 m long plank, PQ, having a mass of 8 kg. You set up the plank with the pivot at X, 0,5 m away from point P. Your friend stands at point Y, 0,2 m away from the pivot. In order to balance the plank horizontally, a 2 kg mass is hung 2 m away from the pivot.

7.1 7.2

Draw a labelled force diagram indicating ALL the forces acting on the friend, the plank and the mass while the plank is horizontal. Calculate the weight of your friend.

(3) (6) [9]

P

2 kg

0,5 m

0,2 m

2 m

X Q Y 8 kg



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QUESTION 8 The following extract was part of an article published in January 2005:

'Cape Town burning' Barring lightning, which is very rare here, fires can only really be caused in three ways: cigarette butts (probably the most common, so many fires start next to roads), deliberate lighting, or broken glass causing the veld to ignite. Humans are responsible for all three.

8.1 8.2

What type of lens must a broken glass bottle represent for it to cause a veld fire? Make a labelled sketch to explain how a broken glass bottle can cause a veld fire.

(2) (6)

A convex lens (L) of focal length 8 cm, is placed in a lens holder on a long bench. A pin (PQ), 5 cm long, is placed vertically in front of the lens and 15 cm away from the optical centre of the lens. Answer QUESTION 8.3 on the attached GRAPH PAPER.

8.3 On the attached graph paper:

• Use the grid lines and a suitable axis. • Locate the point F on the right-hand side of the lens on the axis. • Use a ray diagram to show how an image is formed.

(4) 8.4 Use the ray diagram and determine:

8.4.1 The nature of the image 8.4.2 The image distance

(2) (2) [16]

5 cm

Q 15 cm

P Lens (L)



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QUESTION 9

Call for MP3 hearing risk warning

MP3 players should carry warnings that users risk damage to their hearing by having the volume too high. The faintest sound that the human ear can hear, called the threshold of hearing, is 0 dB. At sounds of intensity of 120 dB the ossicles vibrate so strongly that they strike the walls of the middle ear. A sustained sound level of 85 dB may cause permanent damage to the inner ear. The table below shows sounds of different intensities.

SOUND SOUND LEVEL (dB)

Threshold of hearing 0 Whisper 20 Normal conversation 60 First danger level for ear damage 85 Walkman and MP3 at maximum volume 100 Front rows of rock concert 110 Loud music in a club 110 Threshold of pain 120 Jet aircraft 50 m away 130 Instant perforation of ear drum 160

Use the data in the table above and the information in the passage to answer the following questions:

9.1 9.2 9.3

Explain why continuous listening to music through headphones (for example an MP3 player) at maximum volume will affect your hearing. People working near jet aircrafts sometimes experience pain in their ears. Explain why they experience ear pain. Suggest what they can do to prevent ear damage. Suggest a reason why housing developments should NOT be too close to an airport.

(2) (3) (2)



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9.4

The wave patterns (A and B) below were obtained on the screen of an oscilloscope for sounds of different loudness. One of the wave patterns was produced by a whisper and the other one by a normal conversation.

Which pattern represents the normal conversation? Give a reason for your

answer.

(3) [10]

QUESTION 10 A train driver of a moving train sees an obstruction on the track ahead when the train was in position 1 as indicated in the diagram below. He sounds the horn at position 1 and receives the echo 2 s later at position 2. The distance between position 1 and 2 is 272 m. If the speed of sound in the air is 340 m·s-1, calculate the distance between the train at position 2 and the obstacle. Assume the train travelled at constant speed.

[6]

2 s

Position 1 Position 2

272 m

Distance?

B A



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QUESTION 11 Semi-conductors are a small group of materials that are very important today. They are at the heart of the electronic industry and used in many electronic devices such as computers. The Band Theory of Conduction explains how it is possible for insulators to break down, semi-conductors to become conductors and why metals are good conductors.

11.1 11.2

With the aid of a labelled diagram, explain using the Band Theory of Conduction, why current can flow through a metal. Semi-conductors become excellent conductors at high temperatures. Give a reason for this phenomenon.

(4) (2) [6]

QUESTION 12 A capacitor is an electrical component, which can store electric energy. Capacitors are used in many devices and electronic circuits such as radios, camera flashes, computer keyboards, energy backups in computers and laptops in case of power failure, time delay circuits, such as alarm systems, et cetera.

12.1 What is the primary function of a capacitor in an electric circuit? (1) Two parallel plates are arranged to form a capacitor. The area of each plate is 0,02 m2. The plates are separated by a 0,004 m air gap.

12.2 Calculate the capacitance of the capacitor. (4) The capacitor is connected across a 500 V source as shown below: 12.3 12.4 12.5 12.6

Calculate the charge on each plate. State TWO practical ways in which the charge stored on the plates of the capacitor can be increased. What name is given to the insulating material, which fills the space between the plates of a capacitor? Using your knowledge of capacitors, explain to a friend why it is dangerous for an unqualified person to open the back cover of a television while it is in operation.

(3) (2) (1) (2) [13]

+Q -Q

500 V



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QUESTION 13 A transformer is an important application of Faraday's law. It is manufactured by winding copper wire around a soft iron core. Transformers operate on the principle of mutual induction. A transformer in the school laboratory is used to change 220 V into 12 V needed for a ticker timer to operate.

13.1 13.2

Explain what is meant by mutual induction. Explain why a soft iron core is used, around which the copper wire is wound.

(3) (2)

13.3 Is this a step-up or a step-down transformer? (1) 13.4 Calculate the number of turns in the secondary coil if the primary coil has

50 turns.

(4) [10]


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QUESTION 14 In the circuit represented below, each cell has an emf of 1,6 V and an internal resistance of 0,25 Ω. Two resistors of 10 Ω and 30 Ω are connected in parallel and the ammeter is connected such that it measures the circuit current.

Switch S is open. What is the reading on the following:

14.1 1.42

Voltmeter V Ammeter A

(1) (1)

Switch S is now closed. Calculate the following:

14.3 14.4 14.5

The effective resistance of the parallel combination of resistors The reading on ammeter A The reading on voltmeter V

(4) (5) (3) [14]

TOTAL SECTION B:

GRAND TOTAL:

115 150

10 Ω

30 Ω

S

V

A



DATA FOR PHYSICAL SCIENCES GRADE 11

GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 11

TABLE 1: PHYSICAL CONSTANTS/TABEL 1: FISIESE KONSTANTES

NAAM/NAME SIMBOOL/SYMBOL WAARDE/VALUE Acceleration due to gravity Swaartekragversnelling

g 9,8 m·s-2

Speed of light in a vacuum Spoed van lig in 'n vakuum

c 3,0 x 108 m·s-1

Gravitational constant Swaartekragkonstante

G 6,67 x 10-11 N·m2·kg-2

Coulomb's constant Coulomb se konstante

k 9,0 x 109 N·m2·C-2

Charge on electron Lading op elektron

e- -1,6 x 10-19 C

Electron mass Elektronmassa

me 9,11 x 10-31 kg

Permittivity of free space Permittiwiteit van 'n vakuum

0ε 8,85 x 10-12 F·m-1



TABLE 2: FORMULAE/TABEL 2: FORMULES MOTION/BEWEGING

tavv if Δ+= 2i ta

21tvx Δ+Δ=Δ

xa2vv 2i

2f Δ+= t

2vvx if Δ⎟⎠⎞

⎜⎝⎛ +

=Δ

FORCE/KRAG

ma=Fnet mvp=

221

rmGmF= (G = 6,67 x 10-11 N·m2·kg-2) if mvmvptF −=Δ=Δ

N

(max)ss F

f=μ

N

kk F

f=μ

rF⊥=τ WEIGHT AND MECHANICAL ENERGY/GEWIG EN MEGANIESE ENERGIE

mgFg = U = mgh=Ep

K = 2k mv

21

=E

WAVES, LIGHT AND SOUND/GOLWE, LIG EN KLANK

λ= fv or/of v νλ= f1T = or/of

ν=

1T

ELECTROSTATICS/ELEKTROSTATIKA

221

rQkQ

=F (k = 9,0 x 109 N·m2·C-2) qF

=E

2rkQE= (k = 9,0 x 109 N·m2·C-2)

dVE=

QW

=V QEsW =

rQkQU 21= (k = 9,0 x 109 N·m2·C-2)

VQC=

dA

C 0ε= ( 0ε = 8,85 x 10-12 F·m-1)


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TABLE 2: FORMULAE/TABEL 2: FORMULES (continued/vervolg) ELECTROMAGNETISM/ELEKTROMAGNETISME

tN

ΔΔΦ

−=ε BA=Φ

p

s

p

s

NN

VV

= qvBF =

CURRENT ELECTRICITY/STROOMELEKTRISITEIT

tQIΔ

= IVR=

r)I(R/EMKEMF += ...rrrR 321 +++=

...r1

r1

r1

R1

321

+++=


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NAME/EXAMINATION NUMBER: NAAM/EKSAMENNOMMER:

ANSWER SHEET/ANTWOORDBLAD QUESTION 1/VRAAG 1 1.1 (1)

1.2 (1)

1.3 (1)

1.4 (1)

1.5 (1)

[5]

QUESTION 2/VRAAG 2 2.1 (1)

2.2 (1)

2.3 (1)

2.4 (1)

2.5 (1)

[5]

QUESTION 3/VRAAG 3 3.1

3.2

3.3

3.4

3.5

3.6

(2)

(2)

(2)

(2)

(2)

(2) [10]

QUESTION 4/VRAAG 4 4.1 A B C D 4.2 A B C D 4.3 A B C D 4.4 A B C D 4.5 A B C D (5 x 3) [15] TOTAL SECTION A/TOTAAL AFDELING A: 35




QUESTION 6.2/VRAAG 6.2

FORCE (N)

MASS (Trolley-units)

ACCELERATION (m·s-2) MASS

1

2,5 1 4,4

2,5 2 2,8

2,5 3 2,3

2,5 4 1,9

Physical Sciences/P1 (Physics) 2 DoE/November 2007 NSC

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QUESTION 8.3/VRAAG 8.3

Lens (L)

Q

P

F

5 cm

final qp - physical science p1 physics - nov...

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