sci physics prelim 09 4e5na p2

14
BUKIT MERAH SECONDARY SCHOOL PRELIMINARY EXAMINATION 2009 Secondary 4 Express/ 5 Normal (Academic) SCIENCE 5116/02, 5117/02 PAPER 2 Physics Duration: 1 h 15 min Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Name: _________________________ ( ) Score: _____ Class: _____________ READ THIS INSTRUCTIONS FIRST Write your name, index number and class in the spaces at the top of this page. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions. Write your answers in the spaces provided on the question paper. Section B Answer any two questions. Write your answers on the lined paper provided and, if necessary, continue on separate answer paper. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. FOR EXAMINER’S USE Section A Section B TOTAL This question paper consists of 14 printed pages.

Upload: topcat

Post on 16-Nov-2014

279 views

Category:

Documents


1 download

TRANSCRIPT

Page 1: Sci Physics Prelim 09 4E5NA P2

BUKIT MERAH SECONDARY SCHOOL PRELIMINARY EXAMINATION 2009

Secondary 4 Express/ 5 Normal (Academic)

SCIENCE 5116/02, 5117/02 PAPER 2 Physics Duration: 1 h 15 min Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School Bukit Merah Secondary School

Name: _________________________ ( ) Score: _____ Class: _____________ READ THIS INSTRUCTIONS FIRST Write your name, index number and class in the spaces at the top of this page. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions. Write your answers in the spaces provided on the question paper. Section B Answer any two questions. Write your answers on the lined paper provided and, if necessary, continue on separate answer paper. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question.

FOR EXAMINER’S USE Section A

Section B

TOTAL

This question paper consists of 14 printed pages.

Page 2: Sci Physics Prelim 09 4E5NA P2

2

SECTION A (45 marks) Answer all the questions in the spaces provided. Show all necessary working. Marks are indicated in brackets at the end of each question. 1. The motion of a race car was monitored during a race and part of its speed-time graph is shown

below.

a) Define the term ‘velocity’. [1]

b) Does a race car travel at constant velocity when it goes around a bend? Explain your answer. [1]

c) i) During which segment of the car’s motion does it experience uniform acceleration? [1] ii) Calculate the distance traveled by the race car when it experienced uniform acceleration. [2]

\ Distance travelled =

Speed/ ms-1

Time /s 0

15

20

25

30

5

10

1 2 3 4 5 6 7 8 9 10 A

B C

D

Page 3: Sci Physics Prelim 09 4E5NA P2

3

2. A man pushes a box of mass 15 kg across a floor from rest and reaches a final velocity of 2 m/s after 5 s.

a) Calculate the acceleration of the box. [1] Acceleration =

b) Calculate the resultant force acting on the box. [2] Resultant force =

c) If the man applied a constant force of 20 N to push the box, calculate the frictional force acting against the box. [1] Frictional force =

3. Some students decide to hold a barbecue to celebrate their graduation from school. During the barbecue, meat was pierced on iron forks with wooden handles and grilled over a fire.

a) Suggest why using iron forks with wooden handles would be better than using a fork made completely with iron. [2]

b) The metal grilles of some barbecue pits were silver in colour while some grilles were black in colour. Suggest and explain which grille would help to cook food faster. [2]

Page 4: Sci Physics Prelim 09 4E5NA P2

4

4. The figure below shows an object placed in front of a thin converging lens. The positions of the focal points are marked F.

a) On the figure above, draw 2 suitable rays from the top of the object to determine the position of the

top of the image formed. Mark the position I, of the top of the image. [3]

b) State a real life application that uses this arrangement of lens and object. [1]

c) State what is meant by critical angle. [1]

d) Calculate the critical angle for the lens if the refractive index of the lens’ material is 1.50. [2]

Critical angle

object F F 2F 2F

Page 5: Sci Physics Prelim 09 4E5NA P2

5

5. Many television programs are transmitted ‘live’ via satellite to allow people at different locations to view the program at the same time.

a) State what is meant by a transverse wave. [1]

b) State an application for each of the following components of the electromagnetic spectrum. [2]

i) Ultraviolet rays

ii) Infra-red waves

6. A man plucks the string of a guitar while inside an empty hall.

a) State and explain how the sound made by the guitar would change if

i) the man plucked harder on the string of the guitar. [1]

ii) the man shortened the vibrating length of string [1]

b) When the man plucks a guitar string, he hears two sounds. The time interval between the two sounds was 0.40 s. If the man was 65 m away from the wall as shown in the figure below, calculate the speed of sound. [2]

Speed of sound =

Wall

65 m

Page 6: Sci Physics Prelim 09 4E5NA P2

6

7. Draw the electric field pattern between two isolated point charges as shown below. [2]

8. In the circuit shown below,

a) Calculate the effective resistance of the two resistors connected in parallel as shown in the circuit

below. [2]

Effective resistance =

b) How would the addition of a 2 Ω resistor between A and B, in parallel with the original resistors, affect the current in the battery? Explain your answer. [2]

- -

4 Ω

8 Ω

6 V

A B

Page 7: Sci Physics Prelim 09 4E5NA P2

7

9. A lamp in a house has a power of 100 W at 240 V. The cost of electrical energy is $0.20 per kilowatt-hour (kWh).

a) Calculate the cost of using the lamp for 150 hours. [2] Cost =

b) Calculate the current that passes through the lamp when it is working properly. [1] Current =

c) State and explain which of the following fuse ratings would be most suitable for use in the lamp? 1.0 A, 3.0 A, 5.0 A or 10.0 A [1]

10. Bar A, Bar B and Bar C are made of different materials. It is known that the three bars must be a wooden bar, a soft iron bar and a steel bar magnet. The three bars together with a permanent magnet are placed in turns near each other and the results were recorded in the table below

Bar A Bar B Bar C Permanent Magnet

Bar A Attraction No effect Attraction Bar B Attract No effect Repulsion Bar C No effect No effect No effect Permanent Magnet Attraction Repulsion No effect a) Suggest with reasons which bar is a steel magnet. [2]

b) Describe an electrical method for demagnetizing a magnet. You may draw a diagram if necessary. [3]

Page 8: Sci Physics Prelim 09 4E5NA P2

8

11. An experiment is carried out to plot the magnetic field pattern around a long straight wire which is carrying a current by using a plotting compass. The setup is as shown in the diagram below. The plotting compass is placed above a copper wire. When there is no current in the wire, the plotting compass points towards the North. \

A large current now passes through the wire in the direction as shown. a) State and explain what would happen to the compass needle. [2]

b) State what would happen if the compass is placed under the wire. [1]

Page 9: Sci Physics Prelim 09 4E5NA P2

9

SECTION B (20 marks) Answer any two questions.

Write your answers on the lined paper provided and, if necessary, continue on separate answer paper. 1. Elevators use a series of pulleys to operate. A simplified pulley system is shown below. A large

circular wheel is pivoted at its center and a cable is passed around it. A motor pulls on the cable to move the elevator. Assume g = 10 N/kg

a) State the Principle of Moments. [1]

b) If the mass of the elevator was 1800 kg, calculate the force that the motor needs to exert to just lift the elevator off the ground. [2]

c) State the Principle of Conservation of Energy. [1]

d) State the overall energy changes for using the motor to lift the elevator to a height of 12 m above the ground. [1]

e) If an accident occurs and the elevator drops from rest, at a height of 12 m from the ground,

i. Calculate the velocity of the elevator just before it hits the ground. [3]

ii. If the elevator was prevented from crashing into the ground by an emergency braking system which exerted a power of 5 kW over a period of 2 s, calculate the work done by the braking system. [2]

Elevator

Motor

1.50 m 1.50 m

pivot

Page 10: Sci Physics Prelim 09 4E5NA P2

10

2. A pail of water was left on the ground on Earth as shown below.

a) Calculate the mass of the water in the pail if it was completely full. Assume the density of water to

be 1000 kg/m3. [3]

b) The pail was soon emptied and filled with a liquid X of higher density than water and placed on the ground. After a while, the pail seen to have sunk into the ground. Suggest why this has happened [3]

c) The pail is now emptied again and filled with water and brought to the surface of the Moon in an experiment.

i. State what is meant by gravitational field. [1]

ii. If the gravitational field strength of the Moon is 1.6 N/kg, calculate the weight of the water on the Moon. [1]

iii. State what is meant by inertia. [1]

iv. Suggest and explain whether there would be any difference in trying to start the pail moving on the Moon and on Earth. [1]

Surface area = 0.50 m2

Height = 1.20 m

Pail of water

Ground

Page 11: Sci Physics Prelim 09 4E5NA P2

11

3. The diagram below shows a simple electromagnet. Coils of wire are wrapped around a core AB. a) The switch S is now closed and opened after 5 minutes. State and explain what would happen if,

i. The core AB was made of soft iron and some soft iron nails are placed at end B. [2]

ii. The core AB was made of steel and some soft iron nails are placed at end B. [2]

b) In an experiment, some apparatus were set up as shown below.

i. Calculate the current flowing through the aluminum rod if the rod has a resistance of 2 Ω. [2]

ii. Calculate the amount of charge flowing through aluminum rod over a period of 4 s. [1]

iii. State how the aluminum rod would move if the switch was now closed. [1]

iv. State the effect on the movement of the aluminum rod when the current is increased. [1]

v. State the effect on the movement of the aluminum rod when the direction of current is reversed. [1]

Battery

S

A B

e.m.f = 6 V

Page 12: Sci Physics Prelim 09 4E5NA P2

12

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

Page 13: Sci Physics Prelim 09 4E5NA P2

13

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

Page 14: Sci Physics Prelim 09 4E5NA P2

14

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

-End of paper-