Physics Form 4 Page 1 of 9 Half-Yearly T2/2016-2017

Answer ALL questions showing your working

Where necessary give your answers correct to 2 decimal places.

Table of Formulae

Acceleration due to gravity g = 10 m/s² Average speed = total distance v = u + at a = (v – u) total time t s = ut + ½at2 s = (u + v)t v2 = u2 + 2as 2 Refractive index n = real depth Refractive index n = speed of light in air apparent depth speed of light in other medium Magnification = height of image = image distance from lens height of object object distance from lens Speed of wave v = fλ Periodic time T = 1 f Area of a triangle = ½bh Area of a trapezium = h(a + b) 2

For examiners’ use only

GIRLS ’ SECON DARY , MRIEHEL

HALF YEARLY EXAMINATIONS

2016/2017

FORM: 4 PHYSICS Time: 1½ hrs

Name:________________________________ Class:___________

Question 1 2 3 4 5 6 7 8 Theory Practical Total

Max. Mark 8 8 8 8 8 15 15 15 85 15 100

Score

Track 2

Physics Form 4 Page 2 of 9 Half-Yearly T2/2016-2017

SECTION A – This section carries 40 marks

1. This question is about optics

a) The diagram shows a ray of light incident onto a plane

mirror AB.

i) OX is the ____________________ ray while OY is

the _________________________ray. [1]

ii) Find the angle of incidence i. [1]

_____________________________________________

iii) What is the angle of reflection r? __________________ [1]

iv) Tamara wrote some notes from her observations, some of which are wrong.

Identify which statements are true and which are false. [3]

Statement True/False

i) If the angle of incidence is 45⁰, the angle of reflection

should be double the size. __________

ii) The normal should be drawn at 90⁰ to the plane mirror. __________

iii) Reflection occurs when waves pass from one medium to another. __________

b. Complete the following diagram

showing the refracted and

emergent rays. [2]

2. This question is about the equations of motion.

A van travelling with an initial velocity of 72 km/h

skids to a stop, moving a distance of 25 m.

a) Find the initial velocity of the van in m/s. [2]

b) What is the final velocity of the van? [1]

incident ray

air

air

glass

A B 55

i r

X Y

N

O

Physics Form 4 Page 3 of 9 Half-Yearly T2/2016-2017

c) Calculate the deceleration of the van. [3]

d) Find the time it takes to stop. [2]

3. This question is about motion

Ruth decides to use the apparatus shown in

the diagram to find a value for the acceleration

due to gravity “g”.

a) She uses a particular method to find the value of g.

Indicate the order of numbers 2 to 4 in which the

steps of the experiment have to be performed. [3]

Ruth then proceeds to do the experiment.

b) The initial speed of the ball bearing is ______________________________________ [1]

c) Ruth uses a ___________________________to measure the height fallen by the metal ball. [1]

d) She then decides to repeat the experiment using a heavier metal ball together with a stopwatch to

measure the time taken by the ball to fall.

i) Does a heavier metal ball make a difference in the measured value of “g”? Why? [2]

ii) Using a stopwatch instead of the electronic timer is not such a good idea. Why? [1]

The apparatus was set up as shown. 1

The digital timer stops as the metal ball passes in front of the photodiode.

The metal ball is attached to the electromagnet.

As the switch is closed, the metal ball falls and the electronic timer starts.

Ball bearing

Electromagnet

Photodiode

Pad

stand

Physics Form 4 Page 4 of 9 Half-Yearly T2/2016-2017

4. This question is about optics

During a Physics lesson, John and Maria were supplied with an optical bench as shown in the diagram.

a) Which distance, X or Y represents the:

(i) object distance, ____________ [1]

(ii) image distance ____________ [1]

b) The two students use a convex lens having a focal length of 2 cm. They vary the object

distance u and measure the corresponding image distance v.

The table shows the reading obtained by the students and the corresponding magnification

m in each case.

Object distance u/cm 2.8 3.0 3.3 4.0 4.5 6.0 12.0

Image distance v/cm 7.0 6.0 5.1 4.0 3.6 3.0 2.4

Magnification m 2.50 2.00 1.55 _____ 0.80 ____ 0.20

c) Fill in the two missing numbers in the table. [2]

d) Plot a graph of magnification m on the y-axis against the image distance v on the x-axis.

Draw the best straight line through the points. [4]

5. This question is about velocity time graphs.

A car is travelling at 25 m/s.

The driver realises that he

has to decelerate immediately

and stop the car as a pedestrian

was going to cross the road.

The driver applies the brakes

and stops the car.

a. On the graph, label the

part AB where the driver

is driving at constant

speed. [1]

object image

Light source

X Y

convex lens

0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0

30

25

20

15

10

5

0

Physics Form 4 Page 5 of 9 Half-Yearly T2/2016-2017

b. Using the graph, calculate the thinking distance travelled by the car. [2]

c. Find the deceleration of the car. [2]

d. Using the graph, find the braking distance of the car. [2]

e. Hence find the total stopping distance of the car. [1]

SECTION B – This section carries 45 marks

6. This question is about Waves

a. Label diagrams 1 and 2 with the appropriate words given in textbox below:

[3]

Diagram 1

Diagram 2

From the above diagrams, answer the following questions:

b. Which of the diagrams represent a transverse wave? _____________________________ [1]

c. Which of the diagrams represent a longitudinal wave? ___________________________ [1]

d. Answer True or False:

i. Electromagnetic waves pass through vacuum while longitudinal waves do not pass

through vacuum. _____________ [1]

ii. The particle movement in transverse waves are parallel to the wave movement.

______________ [1]

wavelength amplitude crest

trough compression rarefaction

Physics Form 4 Page 6 of 9 Half-Yearly T2/2016-2017

e. Look carefully at the diagram below and answer the following questions:

i. What is the periodic time of the wave? ________________________________ [1]

ii. Calculate the frequency of the wave. [1]

iii. If the speed of the wave is 330 m/s, calculate the wavelength of the wave. [2]

f. Complete the following table, using the words given in the textbox. [2]

Gamma

Rays __________ __________ __________

Infra Red

Rays __________ Radiowaves

g. Ultrasound waves have a very high frequency beyond human

hearing range. However, these sounds are very much used by

animals such as bats and dolphins. Humans too make use of

these sounds when studying the seabed or to track any sunken

vessels.

The diagram shows a vessel using the echo sounder to

determine the depth of the sea.

If a pulse was sent to the seabed and took 10 s to reach the

seabed, calculate the depth of the sea if the speed of sound

in water is 343.2 m/s. [2]

UltraViolet Microwaves X-rays Visible light

Physics Form 4 Page 7 of 9 Half-Yearly T2/2016-2017

45° 45° object

45°

45°

A

B

white light

R (Red)

screen

7. This question is about light waves.

(a) Mia shines a ray of light on a 60°-60°-60° glass prism. She wants to investigate what happens

when white light passes through a prism.

i. Complete the diagram to show how the violet light is produced on the screen.

Write V at the place where this colour would be seen. [3]

ii. The violet light is (reflected, refracted) the most because it is (slower, faster) than the

red light in glass. [2]

(b) Mia then investigates how a periscope works. This periscope consists of two 45°-90°-45° glass

prisms. The critical angle of glass is 42°.

i. At points A and B _______________ _______________ ___________________ is

taking place. This effect can take place because the angle of _______________ is

greater than the critical angle. [2]

ii. Give one other use where this effect takes place. ___________________________ [1]

Physics Form 4 Page 8 of 9 Half-Yearly T2/2016-2017

(c) Mia then experiments with a convex lens. She placed an object 1 cm high 5 cm in front of the

lens. The lens has a focal length of 3 cm. Note: 1 square represents 1 cm.

i. Complete the ray diagram to show how the image of the object is produced. [3]

ii. Give two characteristic of the image formed by choosing the correct word from the

following:

‘upright or inverted’ __________________ [1]

‘real or virtual’ __________________ [1]

iii. Measure the image distance. ______________________________________________ [1]

iv. This lens can be used in a ________________________________________________. [1]

8. This question is about Freefall

Sarah drops a piece of plasticine of mass 135 g from a bookshelf and takes 0.6 s to reach the ground.

a. Write down the name of the force acting on the plasticine shown in the diagram. [1]

b. Find the mass of the plasticine in kg. [1]

F F

O

plasticine

_____________

Physics Form 4 Page 9 of 9 Half-Yearly T2/2016-2017

c. What is the initial velocity of the plasticine? ___________________________ [1]

d. Fill in the blanks using appropriate words:

The piece of plasticine falls to the ground with an acceleration of ______________.

This type of acceleration is called the acceleration due to _________________ and acts

_______________________. [4]

e. Find the velocity just before the plasticine hits the ground. [2]

f. Calculate the height fallen by the plasticine. [2]

g. If a larger piece of plasticine is dropped from the same height it takes _______________ time

to reach the ground.

If Sarah attaches a small parachute to the plasticine, the plasticine takes __________________

time to reach the ground and reaches the ground with __________________ speed since now

the parachute has more _______________ ________________ acting against it. [4]

END OF PAPER

PLEASE CHECK YOUR WORK!