GOZO COLLEGE. Half Yearly Examinations for Secondary Schools FORM 4 PHYSICS TIME: 1h 30min

Transcription

1 GOZO COLLEGE Track 3 Half Yearly Examinations for Secondary Schools 2016 FORM 4 PHYSICS TIME: 1h 30min Name: Class: Answer all questions. All working must be shown. The use of a calculator is allowed. Where necessary take acceleration due to gravity g = 10m/s 2. Forces Motion Optics W = mg v = u + at s = ut + ½ a t 2 s = (u+v) t 2 Average speed = Total distance Total time n = speed of light (air) speed of light (medium) m = h i /h o v 2 = u 2 + 2as n = real depth apparent depth m = v/u Others Area of triangle = ½ b h Area of trapezium = ½ (a + b)h Waves v = f λ f = 1 T Number Total Maximum mark Actual mark Actual Mark Total Theory Total Practical Final Mark Maximum Mark Physics Form 4 Secondary Track Page 1 of 8

2 SECTION A Each question carries 8 marks. This section carries 40 marks of the total marks for this paper. 1. A slinky spring is stretched on a table. A wave travels from end A to end B. a) Draw on the diagram how point X will move when a transverse wave passes along the spring.[1] b) Give one example of a transverse wave and one example of a longitudinal wave. Transverse: : Longitudinal: [2] c) If distance between A and B is 1.5 m and it takes 2 seconds for the wave to travel, calculate the speed of wave. [2] d) Determine the frequency of this wave if there are 12 waves between A and B. [1] e) Calculate the wavelength of this wave. [2] 2. Astronauts on the Moon wear special suits designed to prevent dangerous radiation from reaching their bodies. a) Name two radiations present on the Moon that can harm the astronauts. [2] b) State the speed in a vacuum of these electromagnetic waves. [1] c) Can sound waves be present on the moon? Explain. [2] Page 2 of 8 Physics Form 4 Secondary Track

3 d) Which types of waves can astronauts use to communicate with someone on earth? [1] e) If the signal sent from the Moon takes 1.28 s to reach the Earth and the velocity of the signal is m/s calculate the distance between the moon and the earth. [2] 3. A ray of light is incident on a glass block passes through the glass and is reflected by the mirror at the opposite side. a) Draw on the diagram above the path followed by a ray of light as it enters the glass block and is reflected by the mirror. [3] b) What is the relationship between the angle of incidence and the angle of reflection on the plane mirror? [1] c) What happens to the speed of light as it enters the glass block? Explain. [2] d) Calculate the speed of light in the glass block if refractive index of glass is 1.5 and speed of light in air is m/s. [2] Physics Form 4 Secondary Track Page 3 of 8

4 Distance - Km 4. The following distance time graph shows Amy s walk around the countryside. 10 A Time - hours a) After how many hours does Amy stop for a break during her walk? [1] b) What is the total distance walked by Amy? [1] c) How long did Amy take to arrive to point A? Give answer in seconds. [2] d) Calculate the average speed of Amy s walk. [2] e) Amy walks faster before or after the break? Explain your answer. [2] Page 4 of 8 Physics Form 4 Secondary Track

5 5. The diagram below shows water waves in a ripple tank moving from deep to shallow water. a) a) Label the incident ray on the diagram and mark the wavelength of these waves. [2] b) Complete the diagram to show the water waves in the shallow water. [2] c) What name is given to this change of direction of the water waves? [1] d) Complete the following sentences by underlining the correct word or phrase in the brackets.[3] (i) When the wave passes into shallow water the wavelength (Increases / decreases / stays the same). (ii) When the wave passes into shallow water the speed of the wave (Increases / decreases / stays the same). (iii)when the wave passes into shallow water the frequency of the wave (Increases / decreases / stays the same). Physics Form 4 Secondary Track Page 5 of 8

6 SECTION B Each question carries 15 marks. This section carries 45 marks of the total marks for this paper. 6. Sonar is widely used for mapping the sea bed and for tracking undersea objects. Sonar is high frequency sound known as ultrasound. a) Give a possible frequency for sonar waves. [1] b) Can these sounds be heard by human beings? [1] distance - m time - s c) The distance travelled by sonar was measured for different time intervals. i. Plot a graph of distance on the y-axis against Time on the x axis. [5] ii. From the graph, what is the relationship between distance and time? [1] iii. From the graph or otherwise, find the velocity of sound waves in water. [1] d) A fishing boat, using sonar, sends out an ultrasound pulse into the water. i. Two echoes are received back, one later than the other. Explain why. [2] ii. If the first echo is received after s, calculate the depth of the shoal of fish. [2] iii. Give two other uses of ultrasound in everyday life. [2] Page 6 of 8 Physics Form 4 Secondary Track

7 7. (a)a child steps out in the path of a car in a busy street. The graph shows how the speed of the car changes from the moment the driver sees the child until the car stopped. i. What is the driver's reaction time in seconds? [1] ii. Name two factors affecting the driver s reaction time. [2] iii. Calculate the braking time taken by the car to stop. [1] iv. Calculate the deceleration of the car while the brakes are being applied. [2] v. Calculate the total distance travelled by the car from the moment the driver saw the child. [2] (b) An apple on a tree fell down to the ground below. i. What would be the acceleration of the apple? [1] ii. State the initial velocity of the apple. [1] iii. Calculate the final velocity with which it hits the ground if it takes 0.9s to hit the ground. [2] iv. Calculate the height of the apple above the ground. [3] Physics Form 4 Secondary Track Page 7 of 8

8 8. Jeremy was investigating the acceleration of free fall using a falling card and a data logger. a) Label the apparatus in the adjacent diagram.[3] b) An important piece of apparatus is missing in the above setup. What is it? [1] c) Describe briefly how Jeremy should carry out this experiment. [3] d) Name two precautions that need to be taken. [2] e) What two measurements must Jeremy take to find the acceleration of freefall? [2] f) How can Jeremy present his results? [2] g) In one experiment when the card was dropped from a height of 0.8 m the time recorded by the data logger was found to be 0.39 s. Calculate the value for the acceleration due to gravity obtained by Jeremy. [2] Page 8 of 8 Physics Form 4 Secondary Track