San Ġorġ Preca College Secondary School, Blata l-Bajda
Half-Yearly Examinations - February 2015
PHYSICS / Track 3 / Form: 3 / Time: 1 hour 30 min
Name & Surname: / Class: / Index No:
Teacher:

Answer ALL questions in the spaces provided on the Examination Paper.

All working must be shown. The use of a calculator is allowed.

Where necessary take the acceleration due to gravity g = 10 m/s2.

Good Luck!

Equations for Half-Yearly Exam - Physics
Volume / Volume = length x breadth x height
Density / r = m

Force / W = m g
Work Done / Work Done = F x s
Power / P = Work Done

Moment of a Force / M = F x s
Motion /

Marks Grid: For the Examiners’ use ONLY

Question No. / 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

Section A This section carries 40 marks.

1. a. Complete the following table.

No. / Physical Quantity / S.I. Symbol / S.I. Unit
i. / kg
ii. / force
iii. / time
iv. / m2
v. / r
vi. / V

b. Complete the following statements:

i. A vector physical quantity has both size and ______.

ii. Name a scalar physical quantity from the above table. ______.

2. a. Which apparatus is used to measure the:

i. time taken for Joseph to run up a flight of ten steps? ______.

ii. volume of some warm milk? ______.

iii. length of a 2 m piece of string? ______.

iv. weight of some sugar? ______.

b. Calculate the:

i. mass of 2500 grams of apples in kilograms kg;

ii. time of a 10-minute walk in seconds s;

iii. length of a 5000 cm cable in meters m;

iv. area of a 2000 cm2 chair seat in square metres m2.

3. a. The figure below shows Gregg parachuting vertically downwards towards the ground.

Air resistance and weight are two forces acting on Gregg and his parachute while approaching ground.

i. Draw an arrow labelled ‘A’ to show the direction of air resistance

ii. Draw another arrow labelled ‘W’ to show the direction of Gregg’s weight.

b. The figure below shows Gregg’s brother David driving his new car.

The engine force E and force P are two horizontal opposing forces acting on the moving car. The engine force E is equal to 2000 N.

i. Name force P. ______.

ii. Underline the correct word within brackets in the following statement:

Force P tries to (slow down / speed up) the car.

iii. Calculate the size of force P given that the resultant force F acting on the car is 1500 N.

4. a. Complete the sentences below using any of the following:

changes; does not change, mass

i. the amount of particles that make up an object is a measure of its ______.

ii. When an object travels in space, its mass ______but its weight ______.

b. A space craft carrying a 100 kg probe travels from Earth to Mars. The pull of gravity on Mars is 3.7 N/kg. The pull of gravity on Earth is 10 N/kg. Calculate the:

5. Nathan of mass 75 kg climbed up to the top of a cliff.

The vertical height of the cliff is 80 m.

a. Calculate:

i. Nathan’s weight,

ii. the work done by Nathan to reach the top of the cliff.

b. Nathan picks up an apple-sized stone from the top of the cliff and drops it to the valley below.

i. Name the energy possessed by the stone at the top of the cliff just before Nathan drops it. ______

ii. Name the energy possessed by the stone just before it hit the rocky floor of the valley.

______

iii. The list below consists of different forms of energy:

light energy; sound energy; potential energy; kinetic energy; heat energy

Choose the correct form of energy to complete the following paragraph:

When the stone hit (touched) the rocky ground of the valley it stopped moving. The ______energy it possessed changed into ______energy and ______energy.

Section B This section carries 45 marks.

6. This question is about the density of iron.

c. Petra and Tamara are asked to find the volume of the nail.

Place the instructions in the table below in the correct order using numbers 1 – 4.

The first one is worked out for you.

the water level rises to volume V2.
Volume of nail Vnail = V2 – V1.
1 / Some water is poured in a measuring cylinder and its volume V1 is recorded.
The nail is gently lowered into the water.

d. Petra and Tamara find that the volume of the large iron nail is 4 cm3 while its mass is 31.48 g. Calculate the density of iron in g/cm3 giving your answer up to one decimal place.

e. After finding the density of the iron nail, the teacher cuts the nail into two unequal parts P and Q as shown in the diagram below.

Part P of the iron nail has a mass of 20 g and occupies a volume of 2.54 cm3.

Calculate the:

i. mass of part Q of the iron nail,

ii. density of part Q of the iron nail given that its volume is 1.46 cm3. (Give your answer in g/cm3 up to one decimal place).

f. Petra and Tamara realise that part Q of the iron nail is much smaller than part P.

i. Underline the correct word in the following sentence:

Part Q of the iron nail has (a larger density than/ a smaller density than/ the same density as) the larger part P since density depends on the (mass/ volume/ material).

ii. The density of water is 1g/cm3. Give a reason why both parts P and Q of the iron nail sink when dropped in a beaker containing water.

7. This question is about the turning effect of forces (moments).

a. The diagram below shows a uniform meter ruler.

i. The point from which the meter ruler can be balanced is referred to as the ______.

ii. Mark this point with the letter ‘C’

iii. How far is this point away from end A of the ruler? Give your answer in metres.

b. Maria places a pivot and a small wooden block weighing 0.5 N on the metre ruler as shown in the diagram below.

i. on the above figure mark the position of the weight of the ruler with an arrow.

ii. Label this arrow with the letter ‘W’.

iii. Calculate the distance between the weight W of the meter ruler and the pivot.

iv. State the direction of the turning effect (the moment) of the weight W. ______

v. Calculate the moment of the wooden block about the pivot.

vi. Given that the system is in equilibrium, the moment of the meter ruler = ______.

vii. Calculate the weight of the meter ruler.

8. This question is about Hooke’s Law and the extension of a spiral spring.

Andrea and Matthew are asked to find the elastic limit of a spring.

a. complete the missing labels of the experimental set-up shown below.

b. Andrea and Matthew apply different weights on to the spring and measure the extension produced by each weight. Andrea draws a table of results as shown below.

stretching force F / N / 0 / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8
extension e / mm / 0 / 2 / 4 / 6 / 8 / 10 / 12 / 15 / 20

Plot a graph of the stretching force F (x-axis) against the extension e (y-axis) on the graph paper provided.

c. Use your graph (or the table of results) to find the:

i. stretching force F in N which produces an extension e of 7 mm, ______

ii. extension e in mm caused by a stretching force F of 5.5 N, ______

iii. maximum (greatest) stretching force F which can be applied to the spring without damaging it. ______

d. Complete the following:

i. The maximum (greatest) stretching force F which can be applied to the spring without damaging it is referred to (called) the ______limit of the spring.

ii. Hooke’s law states that for a spiral spring or wire, provided that the elastic limit is not exceeded the ______is directly proportional to the ______.

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