SHATIN TSUNG TSIN SECONDARY SCHOOL FIRST EXAMINATION PHYSICS S3 Date : 13/12/2004

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1 S FIRST EXAMINATIN PHYSICS P.1 SHATIN TSUNG TSIN SECNDARY SCHL FIRST EXAMINATIN PHYSICS S3 Date : 13/12/2004 Full marks : 72 marks Time allowed : 60 min. Instructions: 1. There are THREE sections in this paper Answer ALL questions 3. nly calculators approved by HKEAA can be used 4. The diagrams in this paper are NT necessarily drawn to scale Section A: Multiple Choice (30 marks) There are 15 questions in the section. Answer ALL question in the Multiple Choice Answer Sheet provided. Choose the best answer. Two or more answers will score No Mark. 1. Which of the following may represent the graph of direct proportional relation between two quantities x and y? A. y B. y x x C y D. y x x The figure shows the graph of y = ax + b. Which of the following is true about the value of a and b? A. a > 0 b = 0 B. a < 0 b = 0 C. a = 0 b > 0 D. a = 0 b < 0 3. Peter s mother always likes to buy oranges from two supermarkets. Each time after shopping, she jotted down the cost. Peter collects the data of one whole year and plots the following two charts. Please state which of following comments is correct? Cost/$ Cost/$ y y = ax + b x No. of oranges Supermarket A No. of oranges Supermarket B A. It is always economical to buy orange at Supermarket B B. The y-intercept on the chart of Supermarket B is caused by error. C. The price of each orange at Supermarket B is lower. D. The curves of both charts are not linear. - to be continued -

2 S FIRST EXAMINATIN PHYSICS P.2 4. For a graph of linear relationship, which of following statements is INCRRECT? (1) It can be represented by the expression y = mx + c. (2) It contains two quantities. (3) It can determine the expression of two quantities in any experiments by graphical method without conversion. A. (1) only B. (3) only C. (1) and (2) only D. (1), (2) and (3) 5. Which of the following about Prefixed is correct? A. Tera > Mega > milli > deci B. Giga > Kilo > micro> pico C. Deci>centi> nano > micro D. Tera > nano> pico> deci 6. Which of the following quantiies is eqaul to 200 ms -1? A. 5 km h -1 B km h -1 C km h -1 D. 720 km h Which of the following equations correctly represents the relationship between current (I) and voltage (V) as shown in the graph? A. 1 I = V B. 1 I =1.5 V C. V I D. V 1. 5 I 8. A best fit line is drawn for the graph of H against T from the following sets of data. Voltage /V Current /A T H Which of the following points will the best fit line pass through? A. (1.5, 3.75) B. (2, 5.10) C. (5, 6.25) D. (4.5, 11.35) 9. Which of the following quantities is/are vector(s)? (1) Distance (2) Displacement (3) Velocity A. (1) only B. (3) only C. (1) and (2) only D. (2) and (3) only 10. Which of the following statements about distance and displacement is CRRECT? A. Displacement is measured along the actual path of travelling B. Distance is always longer than displacement between two points C. Distance is position change between two points D. Distance is always positive but displacement can be positive or negative - to be continued -

3 S FIRST EXAMINATIN PHYSICS P The following table shows the records of travelling of a boy. From A to B From B to C From C to D Time needed 15 seconds 16 seconds 17 seconds Average speed 5 m s -1 4 m s -1 6 m s -1 Which of the following is CRRECT about his travelling? A. The average speed from A to C is 4.50 m s -1 B. The average speed from A to D is 4.00 m s -1 C. The average speed from B to D is 5.03 m s -1 D. The total distance travelled is 240 m. 1 A boy run around an athletic field once and his running records are listed in the following table m m m m Time needed 14 seconds 13 seconds 12 seconds 15 seconds Which of the following is/are CRRECT about his running? (1) His average speed between m is the fastest. (2) His average speed in this race is about 7.41 m s -1 (3) His average velocity in this race is 0 m s -1 A. (1) only B. (1) and (2) only C. (2) and (3) only D. (1), (2) and (3) 13. Which of the following statements is/are CRRECT? (1) Ticker-tape timer can record the motion of a body travelled in both forward and backward direction. (2) The time accuracy recorded by human being with a stop watch can be up to 0.01 s. (3) A scalar-timer can be started by breaking and stopped by making an electric current. A. (1) only B. (3) only C. (1) and (2) only D. (2) and (3) only - to be continued -

4 S FIRST EXAMINATIN PHYSICS P.4 For questions 14 to 15. The following ticker tape is obtained in an experiment with a ticker tape timer of 50 Hz. The tape is divided into 4 portions of equal time interval. The motion begins at the left hand side cm cm 14. cmhow long cm is one tick time? A s B s C. 0.1 s D. 63 s 24.2 cm cm cm cm 15. Which of the following correctly describes the motion of the object? A. The object moves with constant speed. B. The object moves slower and slower. C. The object moves with increasing speed. D. The object does not move at all. Section B : Short Questions (16 marks) There are 5 questions in this section. Answer ALL questions in the answer sheets provided. 1. In the following table, state two differences and two similarities between distance and displacement. Differences 1. Distance 1. Displacement Similarities 1. (4 marks) A car travels due south for 6 km in 3 hours from A to B and then due west for 8 km in 5 hours from B to C. What is i) his total distance travelled and ii) his average velocity from A to C. (4 marks) 3. Describe in details the motion of an object represented by the following graph of velocity against time in the first 12 seconds. **(4 marks)** ** Full sentences are required. - to be continued -

5 S FIRST EXAMINATIN PHYSICS P.5 4. A paper tape is pulled through a ticker-tape timer and 101 dots are found for a period of 2 seconds, what is the frequency of the ticker-tape timer? (2 marks) 5. List in order the four steps of Method of scientific study. (2 marks) Section C : Long Question (26 Marks) There are 2 questions in this section. Answer ALL questions in the answer sheet provided. 6. The following data are taken from an experiment to study the property of a material. Incident angle, i/ o Reflected angle, r/ o Sin i Sin r (a) Complet the table using your calculator. (4 marks) (b) n a graph paper provided, plot a graph of sin i against sin r. Properly label your graph. (6 marks) (c) Find the slope of the graph with two-point form. (2 marks) (d) Write the equation which relates the two quantities, sin i and sin r. (2 marks) 7. The following velocity-time graph represents the motion of a toy train? velocity/ms -1 The graph of velocity against time time/min a) From the graph, find the velocity of the train in (2 marks) (i) the 8 th minute (ii) the 37 th minute b) From the velocity-time graph, complete the following table. (4 marks) Time/min Total Displacement/m c) What is the total displacement travelled in the whole journey? (2 marks) d) Find the average velocity of the toy train in the whole journey? (4 marks) - END F PAPER -

6 S FIRST EXAMINATIN PHYSICS P.6 SHATIN TSUNG TSIN SECNDARY SCHL FIRST EXAMINATIN PHYSICS Answer Sheet S3 Date : Full marks : 72 marks Time allowed : 70 min. Section A: Multiple Choice (30 marks) There are 15 questions in the section. Answer ALL question in the Multiple Choice Answer Sheet provided. Choose the best answer. Two or more answers will score No Mark. Section B : Short Questions (16 marks) There are 5 questions in this section. Answer ALL questions in the answer sheets provided. 1. In the following table, state two differences and two similarities between distance and displacement. Distance Displacement Differences Similarities 1. (4 marks) i) his total distance travelled from A to C (4 marks) ii) his average velocity from A to C 3. Describe in details the motion of an object represented by the following graph of velocity against time in the first 12 seconds. (4 marks) 4. What is the frequency of the ticker-tape timer? (2 marks) 5. List in order the four steps of Method of scientific study. (2 marks) Section C : Long Question (16 Marks) There are 2 questions in this section. Answer ALL questions in the answer sheet provided. 6. a) Complet the table using your calculator. (4 marks)

7 S FIRST EXAMINATIN PHYSICS P.7 Incident angle, i/ o Reflected angle, r/ o Sin i Sin r b) n a graph paper provided, plot a graph of sin i against sin r. Properly label your graph. (6 marks) c) Find the slope of the graph with two-point form. (2 marks) d) Write the equation which relates the two quantities, sin i and sin r. (2 marks) 7. a) From the graph, find the velocity of the train in (2 marks) the 8 th minute : the 37 th minute : b) From the velocity-time graph, complete the following table. (4 marks) Time/min Total Displacement/m c) What is the total displacement travelled in the whole journey? (2 marks) d) Find the average velocity of the toy train in the whole journey? (2 marks)

8 S FIRST EXAMINATIN PHYSICS P.8 Answer Section A: Multiple Choices (15 marks) 1. A 6. D C 7. D 3. C 8. C 4. C 9. D 5. B 10. D 11. C 12 D 13 B. 14 A. 15 C. Section B : Short Questions (16 marks) There are 5 questions in this section. Answer ALL questions in the answer sheets provided. 1. In the following table, state two differences and two similarities between distance and displacement. Differences Similarities Distance 1. magnitude only (Scalar) Measured along the path of travelling 1. same symbol s Displacement 1. magnitude and direction (Vector) Measured in a straight line connected the start and end positions same SI unit of metre (4 marks) A car travels due south for 6 km in 3 hours from A to B and then due west for 8 km in 5 hours from B to C. What is i) his total distance travelled and ii) his average velocity from A to C. (4 marks) i) His total distance travelled : = 14 km 2 2 ii) Total displacement = = 10km His average velocity = 10 km / 8 hours = 1.25 km h -1 = m s -1 3.Describe in details the motion of an object represented by the following graph of velocity against time in the first 12 seconds. (4 marks)** The object starts from at rest and speed up constantly (uniformly) to 12 m s -1 in the first 6 seconds. The object then maintains its speed form another 6 seconds at 12 m s -1 (4 marks)*

9 S FIRST EXAMINATIN PHYSICS P.9 4.A paper tape is pulled through a ticker-tape timer and 101 dots are found for a period of 2 seconds, what is the frequency of the ticker-tape timer? (2 marks) The frequency of the ticker-tape timer : (101-1)/(2) = 50 Hz 5. List in order the four steps of Method of scientific study. (2 marks) bservation Collecting data Analyzing data Conclusion Section C : Long Question (16 Marks) There are 2 questions in this section. Answer ALL questions in the answer sheet provided. 6. The following data are taken from an experiment to study the property of a material. Incident angle, i/ o Reflected angle, r/ o Sin i Sin r a) Complete the table using your calculator. (4 marks) b) n a graph paper provided, plot a graph of sin i against sin r. Properly label your graph. See the graph paper (6 marks) c) Find the slope of the graph with two-point form. (2 marks) m = (y2-y1)/(x2-x1) = ( )/( ) = 1.5 d) Write the equation relates the two quantities, sin i and sin r. The equation is : sin r = 1.5 sin r (2 marks) velocity/ms The following velocity-time graph represents the motion of a toy train? velocity/ms The graph of velocity against time time/min time/min a) From the graph, find the velocity of the train in (2 marks) the 8 th minute : 5 m s -1 the 37 th minute : 0 m s -1 b) From the velocity-time graph, complete the following table. (4 marks) Time/min Total Displacement/m

10 S FIRST EXAMINATIN PHYSICS P.10 c) What is the total displacement travelled in the whole journey? (2 marks) Total displacement = ((5+10)x5/2 + (5+15)x 15 / x 10 /2)x 60 = m d) Find the average velocity of the toy train in the whole journey? (2 marks) Average velocity = / (40 x 60) = 6.56 m s -1