Physics

Electric Charge and Electromagnetism

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, we will be looking at electric charge and how it can be produced by friction, when two different materials are rubbed against each other. We will discuss the reason why some materials, called conductors, allow electric charge to pass through them and why others, called insulators, do not. Static electricity is charge that is not moving. It can be very useful or it can be very dangerous, and we will look at the reasons for this. We will also discuss the forces that exist between like and unlike electrostatic charges. Positive and negative electrostatic charge will be considered, as well as how a force is produced when a current flows through a conductor in a magnetic field. We will then see how this can be developed to make an electric motor.

Electricity

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, we will consider electricity and its use as a provider of energy. We will look at the difference between direct current, which is supplied by cells and batteries, and alternating current, which is used in mains supply. We will consider the heating effect of a current flowing through a conductor and how electrical energy is transformed to useful energy. The title will also study safety aspects and how insulation, earthing, fuses and circuit breakers can be used to protect appliances, and help minimise the risk of electric shock to the user. The wiring of a domestic plug will be described, and we will discuss how to calculate energy transformed and power. We will consider the National Grid and the high voltages at which electricity is transmitted. Finally, we will discuss the units of measurement used in electricity.

Electromagnetic Induction

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, we will look at the parts of electromagnetic induction that you may encounter in your GCSE studies. Transformers are often the subject of exam questions. We will consider input and output voltages and their relationship with the turns ratio of input and output coils. We will discuss the difference between step-up and step-down transformers and where each is likely to be used. Next we examine the theory of electromagnetic induction, including the actions needed to induce a current in a conductor such as potential difference. This title also covers generators, and how a coil rotating in a magnetic field can produce an alternating current. Instead of a coil rotating in a magnetic field, some generators, or dynamos, have a magnet rotating inside a coil.

Energy and Potential Difference in Circuits

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, we will look at electricity in circuits. We start by studying current in detail, and see how it is derived from the flow of electric charge. Next, we will look at potential difference, more commonly known as voltage, which provides the driving force behind the current. Resistance is something that opposes the current, and it increases in longer wires and wires with a smaller cross sectional area. This title also discusses how current flows through metals and liquid solutions called electrolytes. You will see that in controlled conditions resistance can be very useful, if not essential, when it is necessary to control the current in a circuit. We will look at components that provide resistance, such as fixed and variable resistors. Lastly, we look at circuits and discuss the difference between series and parallel circuits.

Energy Resources and Electricity Generation

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

Electrical devices have become important features in all our lives - just take a look around you. How many electrical devices can you see? All these devices, with many different uses and purposes, can be powered with one form of energy - electricity. Electrical energy is very useful to us because it can be easily transferred from one form to another; it is very versatile. Because energy cannot be created or destroyed, this electrical energy must be transferred from other resources. These resources are one of the things that you will learn about in this title. The energy from these resources must be converted into electrical energy at a power station. You will also learn about how these different power stations work, and the various advantages and disadvantages of them.

Energy Transfer

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title you will learn about energy, which is one of the most important concepts in the whole of physics. You will learn about the conservation of energy, a principle that can be applied from the birth of the universe until right this second. You will learn about the different types of energy, including both the stored potential energy of chemical bonds, the inside of the nucleus, stretched elastic bands and objects raised up high. The title will also consider the different types of energy in use, such as thermal, electrical, light, sound and kinetic, or movement, energy.

Transferring Thermal Energy

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

The transfer of thermal energy is very important in physics and has applications in many industries. In this title, you will learn about the three main ways in which thermal energy is transferred - conduction, convection and radiation. You will learn that conduction is affected by different factors, such as the material in which the heat transfer is occurring, and why these factors are important. You will learn about convection, which only occurs in fluids like water and air, and how it influences ocean currents and the weather. This title also explains thermal transfer by radiation, which brings heat from the Sun to the Earth, and how different surfaces emit and absorb this radiated heat. Finally, we will examine how heat transfer can be prevented, and why the insulating process is important for both people and the environment.

Work and Power

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you will learn about some of the different types of energy: gravitational potential, elastic potential and kinetic energy. Gravitational potential energy is the energy that an object has because of its position in a gravitational field. Elastic potential energy is the energy stored in a stretched elastic object, such as a rubber band or a spring, and kinetic energy is the energy of an object that is moving. You will also learn about how forces transfer energy to heat, and the role this plays in creating waste energy. This prevents processes from being 100% efficient. The title will explore work done', how it relates to energy transfers, and how it is calculated from the exertion of a force over a distance. Finally, you will learn about the rate of doing work, and how power is calculated.

Effects and Uses of Force

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you will learn about the effects of force in different situations. A force is needed to make something happen, like speeding up a moving object. We will discuss weight, a force that always acts downwards and from an object's centre of gravity. We will study circular motion and show that centripetal force is needed to make something move in a circle. Mass is a quantity known as a scalar, and force is a vector. We will discuss what these mean and the difference between the two. All moving objects have momentum, and this title examines how it is conserved in collisions and explosions. We will also consider Newton's second law of motion, and how pressure can be used to convert a small force into a larger one. Moments of force and their application will finally be discussed.

Forces and Movement

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, we will look at potential energy stored as elastic energy: when something is forced to change its shape and tries to revert back to its original shape. This provides kinetic energy in things like catapults and clockwork toys. We will also consider equal and opposite forces in relation to Newton's third law of motion. Friction is a force that opposes movement, and this can be an advantage or disadvantage. This title also discusses stopping distances of cars, and what might make the distances increase. Terminal velocity and the reasons why vehicles need to have a top speed are considered. We examine the earth's gravitational field, and how it affects satellites and space rockets. Finally, we look at the theories of Galileo and Newton and see how they have contributed to our modern understanding of the solar system.

Forces and Shape

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In the first part of this title, we look at the extension of springs and rubber bands. We will consider that extension occurs when a force is applied and that work has to be done when this happens. When work is done, energy is used. This energy is stored as elastic potential energy. Moving gas particles can exert a force on the inside wall of a container, and this is caused by their change in momentum. We will discuss what factors cause change in momentum. In nature, moving air particles, or winds, can exert a massive force, which can be extremely dangerous or harnessed to our advantage. This title also looks at pressure and volume in a fixed mass of gas. We will discuss how pressure is increased when volume is decreased, and how temperature affects both pressure and volume.

Movement and Position

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

This title considers motion. We will look at speed, and how it can be calculated using the speed equation. Measuring the distance of a journey and dividing this by the time it takes gives us the average speed. We will compare this with the 'instantaneous' speed reading as given by a car's speedometer. A journey can be represented by plotting a graph of distance against time. We will look at this, describing the different parts of it in detail. Acceleration is a vector defined as the rate of change in velocity, although in everyday life we think of acceleration as speeding up'. We will look at this more closely and try a few calculations. A graph of speed against time represents a journey in terms of acceleration. This graph will be examined and compared with graphs of distance against time.

Atomic and Nuclear Structure and Radioactivity

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you will learn about atomic structure, which is what lies beneath the surface of everything you see and touch. You will learn about protons, neutrons and electrons, and how they combine to make up the Universe. You will hear about isotopes and what they mean for radioactive decay. We will also look at the three different types of radioactive decay, and how this radioactivity appears in nature. You will discover how radioactive particles and waves can be detected, and how they can be useful and dangerous. We will then be discussing nuclear fission and nuclear fusion. This title also covers how electricity is generated at nuclear power stations, as well as what happens in nuclear reactions. Finally, you'll learn about the history of the atom, and how our knowledge of the Universe's composition has developed over time.

The Rest of the Universe

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title you'll learn about the Universe. We consider the Big Bang theory and what it means for the evolution of the Universe. You will hear how the Universe came to be according to this theory, and how it developed into the state in which we see it now. We also discuss how stars form from clouds of interstellar gas, and how they move between the different stages, including red giant, white dwarf, neutron star and black hole. The title will explore Earth's own Sun and the galaxy in which it resides - the Milky Way. It will also detail how telescopes are used and the different types of telescope that are available to astronomers. Finally, we will consider redshift - what it is, and what it means for the Universe.

The Solar System

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

This title will cover one of the most important interactions in all of physics - the force due to gravity. You will learn about the factors that govern the strength of gravitational forces, the masses of objects and the distances between them, and why gravitational forces are important. We will explore the planets, the differences and similarities between them, and consider the controversy over what constitutes a planet and what doesn't. The title also explains what causes planets to orbit, and what causes moons and other satellites to orbit planets. You will learn about the Earth, its internal structure and the composition of the atmosphere. We will also discuss how humans are affecting its atmosphere. Finally, the title will consider Earth's seasons, detailing what causes them and how they affect life on Earth.

Communications

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

The history of communication dates back to the earliest signs of life. Communication can range from very subtle processes of exchange, to full-blown conversations and, especially in our current time, mass communication. Human communication was revolutionised by speech about 200,000 years ago. Symbols were developed about 30,000 years ago, and writing about 7,000 years ago. On a much shorter scale, there have been major developments in the field of telecommunications in the past few centuries. Most of these developments have revolved around the discovery of electricity. From postal services to telegrams to telephones, most of this revolution was powered by the analogue signal. There has been another revolution in recent years as digital communications have become widely used. In this title, we'll examine what makes these signals what they are and the impact they have on us.

Light and Sound

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In light and sound, we have our two most prominent senses - two of our most vital tools for communicating with the outside world. They are so fundamental to us that the very concepts invade our everyday language. For example, 'listen', 'look', 'see' all have many more meanings in common use than just their scientific ones, which isn't the case with some of the other terms we'll meet. For example, the word 'transparent' is fairly clear in meaning. So, in this title, you'll learn about the science behind sound and the theory of vision.

Mirrors and Lenses

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

Mirrors and lenses - without them we would be lost at sea. One of the many uses we have for reflecting and focusing light is in lighthouses, which beam light out across stormy seas and guide ships safely to harbour. We have known much of the science of lenses for thousands of years, even making them into reading glasses as long ago as 1300! In modern times, we have new materials that allow us to make lenses and mirrors far more accurately for use in fibre-optics and broadband communications. We will address the underlying mechanisms of refraction and reflection, and specifically the requirement to be able to draw ray diagrams to work out the action of a mirror or lens. In this title, we'll break this ancient science down into manageable chunks and focus on each in turn.

The Earth's Layered Structure

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In early human history we believed in a flat Earth, suspended in space or supported by creatures or pillars. As our knowledge and understanding evolved, though, we headed towards a globe idea. As a historical introduction, it is worth mentioning Eratosthenes, a Greek philosopher who lived in Alexandria around 250BC. He was told that on a certain day during summer in a town called Syene, the sunlight shone directly down the well shafts so that you could see to the bottom. Eratosthenes knew the sun was never high enough in the sky to see the bottom of wells in Alexandria, so was able to use this to calculate the circumference of the Earth. He came up with an answer of 40,320 kilometres, which is very close to today's measurement of 40,030 kilometres - not bad for over 2000 years ago!

The Electromagnetic Spectrum

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

There is more to light than just the rainbow of colour that we see around us. All of the colours and images we see are just a small part of one continuous series of waves called the electromagnetic spectrum. We owe our use of the word spectrum', which means appearance' in Latin, and our earliest knowledge about it to Isaac Newton, who published a well-known book called 'Optiks' in 1671. We will hear more about Newton when we look at the visible part of the spectrum later. Since Newton's day, we have expanded our knowledge and understanding of the spectrum to include everything from gamma radiation to radio waves, and so have split this title up accordingly.

Units and Properties of Waves

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

Welcome to the title on the properties and definitions of waves. As with many areas of science, it is the units and definitions that are extremely important. For the most part, in this title we'll be discussing the basic properties that apply to all of the things that we loosely clump under the word 'waves'. In the strictest sense, mechanical waves - like water waves and sound waves - are not the same as electromagnetic waves such as light waves. However, most of the mathematics and reasoning of mechanical waves applies to light waves and vice versa.