Preparation for A-Level Physics

Choosing to study A-Level Physics is a wise choice, the A-Level not only gives you many options going forward but also and more importantly enables you to further explore how the world around you works.

In the first year of A-Level Physics you will build on a lot of the material studied at GCSE, but looking at some areas in greater detail, refining the model and tackling more challenging problems. A good physicist is a good problem solver.

Skills a physics student needs

- Imagination and Curiosity: - Looking for new solutions to old problems- Willingness to expand understanding and knowledge beyond the

curriculum- Abstract thinking

- Determination- Hands on approach to experimentation- Embracing failure as a positive outcome- Independent working and perseverance- Meticulous methodology

- Creativity- Collaborative working- Problem solving- Finding new motivation and study skills

And many many more.

Section 1. Maths Skills

Trigonometry is used a lot in this A-Level course so make sure you keep your skills up.

1.1

SOHCAHTOA - using the triangle below, explain in your own words what this means

1.2 Pythagorus - what is pythagorus theorem, explain in your own words with a diagram if you want.

1.3 A little bit of background, for each of the names below find the dates of their lives, where they lived/worked, a key idea they had related to physics or astronomy and one fun fact about their life.

Aristotle Pythagoras Archimedes

1.4 For each of the triangles below find the internal angles and missing lengthsa b

c d

e f

6

5

0.2

0.4

60

42

1251

549

24

18

3 x 10-4

5 x 10-3

1.5 Write the following numbers in standard form and then with an appropriate prefix, the first one has been done for you.

A) 300000000000m A) ……3 x 1011m………… A) …0.3Tm……….

B) 0.401m B)……………………….. B) ………………….

C) 0.0000065m C)……………………….. C) …………………

D) 700000m D)……………………….. D) ………………….

E) 0.1 m E)……………………….. E) ………………….

F) 0.0000004012 m F)……………………….. F) ………………….

G) 1678 m G)……………………….. G) ………………….

H) 2300000000000m H)……………………….. H) …………………..

I) 0.000000007 m I)……………………….. I) …………………..

J) 405690 m J)……………………….. J) …………………..

1.6 Write the following in standard form and state the physics quantity that the unit corresponds to. The first one is done for you.

A) 4nA A) ……4 x 10-9 A……… A) …Current……….

B) 560 nm B)……………………….. B) ………………….

C) 0.3GJ C)……………………….. C) …………………

D) 45TV D)……………………….. D) ………………….

E) 0.08 kN E)……………………….. E) ………………….

F) 36Mm F)……………………….. F) ………………….

G) 67 μs G)……………………….. G) ………………….

H) 0.1 pT H)……………………….. H) …………………..

I) 9.09mJ I)……………………….. I) …………………..

J) 600cPa J)……………………….. J) …………………..

1.7 determine the following values, with an appropriate unit. Leave your answers in both standard form and with a prefix where applicable.

A) 3x108m/s x 4mm B) 9GV ÷ 3x10-3A

C) 2.8x104m/s ÷ 750nm D) 𝜋(1.5mm)2

1.8 Rearrange the following equations

A) W = mg for m = g =

B) EK = 1mv2 m = v = 2

C) VP = NP. VP = NP = VS = NS = VS NS

1.9 Useful mathematical short hand. Find out what the following symbols mean when used mathematically.

A) Δ B) ≈ C) ∝ D) ∑ E) ≠

F) ⊗ G) ± H) ∴ I) ∵ J) ⊙

1.10 For each of the triangles below, find the missing sides labelled x

Section 2 Fundamental Physics Knowledge

Below is a diagram outlining the main content of the A Level Physics course.

23

4.8

9.9 x 10-3

5

22º18º

30º

15º

x

x

x

x

2. Review the fundamentals

The first year of A Level Physics builds on your GCSE knowledge of some of the fundamental physics material, it is important that you ensure you have a good understanding of these.

For each of the topics below there is an example question. Before you attempt the question take some time to review your GCSE notes on the topic. For example for the topic of motion you might want to look at all the equations that include speed, accelerate tin distance, look at all types of motion graphs.

2.1 Motion

Answers 1a)…………………. 2a) ……………….. 2c)…………………b)…………………… 2b)..………………. 2d)…………………

2.2 Forces

2.2.1 Complete the sentences below by choosing the correct word in each pair and crossing out the incorrect word. The sentences refer to a skydiver who has jumped out of a plane and is falling towards the ground.

a When a skydiver first jumps out of an aeroplane, the greater force acting on them is gravity / friction. (1mark)

b The force of gravity will cause them to move upwards / downwards (1mark)

c The skydiver will start to accelerate / decelerate. (1mark) d The acceleration due to gravity on Earth is about 10 / 50 N/kg. (1mark) e Eventually, a skydiver will reach a constant speed called terminal / initial

velocity.(1mark) 2.2.2 The graph shows how the velocity of a skydiver changes with time for a

parachute jump.

a Explain what is happening at each of the points A to E.

A

B

C

D

E

(5marks)

b Match each of the free-body diagrams below to the skydiver at each stage of her journey. Write the correct letter under each diagram.

(5marks)

2.3 Work, Energy and Power

2.3.1 Fill in the spaces in the statements below to complete the sentences. Use the words, numbers or units from the box provided, using each one only once. (10 marks)

a The unit of energy is the …………………… and the unit of power is the

…………………… .

b The energy store of a moving car is mostly …………………… energy.

c If a force of 20 N moves a distance of 30 m then the amount of work

done will be …………………… J.

d A power of 1 W is the same as 1 …………………… .

e The power rating will be greater if work is done over a

…………………… period of time.

f The …………………… that a device is used for and the

…………………… its power rating, the …………………… energy will be

transferred.

600 more longer joule J/s shorter kinetic watt scalar greater

g Energy and power have a size or magnitude, but no specific direction,

so they are …………………… quantities.

2.3.2 Calculate the work done in each of the examples below, including the units in your answer:

a A car being pushed with a resultant force of 800 N for 30 m.

(3 marks)

b A book of mass 850 g being lifted onto a shelf that is 4.5 m above the desk on which it was initially placed.

(3 marks)

c A spring with spring constant 40 N/m being stretched from 12 cm to 20 cm.

(3 marks)

2.3.3 Fill in the missing values in the table below. (5 marks)

Power Energy transferred Time in s

3000 J 60

1200 W 3600

800 W 2.8 × 109 J

0.02 J 2 × 10−3

1.2 kW 900 MJ

2.3.4 A man of mass 85 kg runs up a flight of stairs of height 4.6 m in a time period of 12 s.

a Calculate the man’s power rating when doing this. Include the unit in your answer. (3 marks)

b A girl achieves a power rating of 70% of the man’s power rating when she scales the stairs in a time of 9.6 s. Calculate the mass of the girl. Include the unit in your answer. (4 marks)

2.4 Moments

2.4.1 Determine the size of the force F that is required for the seesaw shown below to be in equilibrium.

(4 marks)

2.4.2 Determine the distance that the 6 N force needs to be from the pivot in order for the beam to balance.

(4 marks)

2.5 Momentum

2.5.1 a Explain why: i momentum is a vector quantity

(1 mark)

ii the total momentum of an exploding bomb is zero before and after the explosion.

(4 marks)

b A squash ball of mass 24 g moves towards a wall with a velocity of 16 m/s. It strikes the wall, remaining in contact with the wall for 0.02 s, before bouncing back into the squash court with a speed of 12 m/s.

Calculate: i the initial momentum of the squash ball as it moves towards the wall

(3 marks)

ii the momentum after the ball hits the wall

(3 marks)

iii the change in momentum of the ball

(3 marks)

2.6 Charge

2.6.1 Fill in the gaps in the following paragraph using the words in the box.

There are two types of charge called .................... and .................... .

Rubbing an .......................... can make it become charged. A body will become .......................... charged if it gains .......................... .

A body will become .......................... charged if it loses electrons.

Metals are examples of .......................... They do not become .......................... when rubbed. (8 marks)

positively insulator negatively positive charged conductors electrons negative

2.7 Current, Potential Difference and Resistance

2.7.1 Complete the diagram below by adding the missing names of the circuit symbols. (5 marks)

2.7.2 a Complete the description of the circuit diagram below.

The circuit contains one ..................... arranged in ..................... with an

open ..................... and a .......................................... .The voltmeter is

arranged in ..................... across the lamp.

(5 marks)

b Write a description of the circuit diagram below. (4 marks)

2.7.3 a Redraw the circuit shown below using the correct symbols. (5 marks)

Draw circuit using correct symbols here

2.7.4 The circuit shown below contains a thermistor arranged in series with a variable resistor, connected to a d.c. input such as a 12 V cell or battery. The resistance of the thermistor decreases as it gets warmer and has a maximum value when it is very cold.

a Describe a use for this circuit. (2 marks)

b Explain why a variable resistor is used in the circuit instead of a fixed resistor. (3 marks)

2.8 Wave Characteristics

2.8.1 Draw lines to match each word to its definition. (4 marks)

Amplitude The number of waves or oscillations per second, measured in hertz, Hz.

Wavelength The time for one wave to pass a given point or the time for one complete oscillation, in seconds, s.

Time period Distance from the rest position to the top of the wave, measured in metres, m.

Frequency Distance from one point on the wave to the identical point on the next wave, measured in metres, m.

2.8.2 The following diagrams show a longitudinal and a transverse wave. Use the diagrams to help you fill in the gaps in the sentences below.

a …………………….......... waves contain compressions and rarefactions.

(1 mark)

b …………………….......... waves travel parallel to the direction of

vibration. (1 mark)

c …………………….......... waves are made when the oscillations are at

90o to the direction of wave motion. (1 mark)

d Sound is caused by …………………….......... waves. (1 mark)

2.8.3 Fill in the table below to show if the observations apply to longitudinal waves, transverse waves or both. Tick the correct box(es) in columns two and three and then explain your answer in column four. (4 marks)

2.9 Properties of Waves

Longitudinal wave

Transverse wave

Observation Transverse wave Longitudinal wave

transfer energy

direction of vibration is at right angle to direction of travel

can be heard

travel through a medium

2.9.1 A sound wave is generated by clapping two wooden sticks together. The students record hearing the echo 1.2 seconds later. The students are standing 210 m from the wall.

a Use this information and the diagram to determine a value for the speed of sound in air.

(4 marks)

b Explain how the investigation could be changed so that the value for the speed of sound obtained would be more accurate.

(2 marks)

2.9.2 An ultrasound signal is sent out by a ship to detect how far beneath the surface the sea bed is. The process is called ‘echo-ranging’. The ultrasound signal has a frequency of 24 000 Hz and a wavelength of 0.63 m. The time between sending the signal and detecting the reflected wave is 0.42 s.

a Explain why the process is called echo-ranging. (2 marks)

b Explain why the equation used to find the distance of the sea bed

beneath the surface can be written as d = (v × t)

(2 marks)

c Calculate the distance from the surface of the water to the sea bed.

(4 marks)

12

2.10 Electromagnetic Spectrum and Beyond

In 1928, it became possible to combine quantum theory and special relativity to describe the behaviour of a free electron moving at speeds near the speed of light. The equation that was created to describe this motion, however, posed a new problem for physicists; it was quadratic in form. You will be aware that quadratic equations like x² = 4 have two possible solutions (x = 2 or x = – 2), and a similar possibility arose with the electron equation. One solution was the expected one of an electron with positive kinetic energy; the other solution allowed the electron to have negative kinetic energy. Neither classical physics nor common sense could accommodate the idea of negative kinetic energy. Further work with the equations showed that the negative energy solutions were identical to the positive energy solutions that would arise from considering a particle of identical rest mass to the electron, but with a positive charge of equal magnitude to that of the electron. In all respects the particles were identical except for their charge. The particle was thought of as an ‘anti-electron’, but has since become known as a positron. This led to the wider interpretation that for every particle there exists a corresponding antiparticle, exactly matching the particle but with opposite charge. This insight opened the possibility of anti-atoms and even entire galaxies and universes made of antimatter. It soon became clear that when a matter particle and its corresponding antimatter particle come into contact, they annihilate each other, The annihilation results in the energy possessed by the particles becoming two high energy photons (γ rays). Hence a positron colliding with an electron will create two γ ray photons travelling in opposite directions. For a time this was thought to be a strange consequence of the theoretical equations but later experiments detected the positron (and other antimatter particles) and their annihilation. Towards the end of the twentieth century, it became possible to detect the γ rays created when electrons and positrons annihilate and use them in order to map the internal organs in the human body. The apparatus used to create these images is known as a PET scanner.

Task Use textbooks and the Internet to find: • the name of the British physicist who formulated the relativistic equation

and suggested the existence of positrons • the name of the American physicist who first detected positrons in his

cosmic ray experiments, and the year in which he made this discovery • how positrons are used in positron emission tomography (PET scans).

Use your research notes to produce an illustrated article for a science magazine outlining the history and application of positrons in modern hospitals. Make sure you use appropriate paragraph breaks, and that the text flows within each section. The meanings of your sentences need to be clear on first reading, and you should use scientific terms correctly. You will also be marked on using appropriate diagrams and the general layout of your article.

Section 3 Extended Reading and Current Events

3.1 Magazines

New ScientistScientific AmericanPhysics World - Published by the Institute of Physics online

3.2 Online Resources

Institute of Physicshttp://www.iop.org/#gref

Hyper physicshttp://hyperphysics.phy-astr.gsu.edu/hbase/index.html

Any interviews with Richard FeynmanEg https://www.youtube.com/watch?v=P1ww1IXRfTA