Every GCSE physics paper normally has at least one question with a mark for the correct interpretation or expression of numbers in standard form. This is a basic skill that is taught as part of GCSE mathematics courses but it holds a great deal of power for scientific calculations that is rarely mentioned at this … Continue reading Standard Form
Why does hot air rise?
Easy question! It's because hot air is less dense than cold air. Except that things aren't really this simple. How does hot air know its own density and the density of the cold air that surrounds it? For that matter, how does hot air know which way is up? You might say that hot air … Continue reading Why does hot air rise?
Specific Heat Capacity and Energy Stores
Two ways are suggested in GCSE Physics for measuring the specific heat capacity of a material. I have already explained the electrical method (see here) but it looks likely, from the advanced information supplied by AQA, that the other method will feature in this summer's Trilogy physics examination. So here's what you need to know … Continue reading Specific Heat Capacity and Energy Stores
Ohm’s Law
Potential difference (voltage) and current are fundamental measurements for electric circuits. Multiply the potential difference across a device by the current flowing through it to get the power rating for that device.Multiply the power rating by the time for which the device is used to get the energy that the device has transferred. All of … Continue reading Ohm’s Law
Resources for Electricity Generation
In school we talk about different ways to generate electricity as a potential exam topic but it's much, much more important than that. Russia's war with Ukraine has brought this fact sharply into focus as people start talking about a boycott of Russian oil and gas. At the same time, the UK is phasing-out its … Continue reading Resources for Electricity Generation
Changes of State
Despite having previously examined a phase-change diagram in detail (here) I haven't yet covered the particle model and how it links to different states of matter. So that topic, which is relevant for both chemistry and physics, is the focus of this article. First let's clarify the terminology... we will be confining ourselves to the … Continue reading Changes of State
Energy Revision – new resource
Energy stores and transfers are one of the really big ideas in physics and this is also a topic that AQA has announced will be in Paper 1 for the Trilogy examination this month. With that in mind, I have created a new revision resource that you can use to check your knowledge and understanding. … Continue reading Energy Revision – new resource
Properties of EM Waves
Electromagnetic (EM) waves are generated by the movement of electrons. In an electric circuit, visible light can be generated when electrons (a current) move through a lamp. Electric circuits can also generate infra-red waves (TV remote controls), microwaves (ovens), x-rays (medical scanners) and radio waves (aircraft ground-to-air communications). These different types of EM waves have … Continue reading Properties of EM Waves
Energy Budget
It is well known that darker surfaces heat up faster than lighter surfaces and reach a higher maximum temperature. But why? When the maximum temperature is achieved, there is a state of thermal equilibrium that is is due to a balance between the rates at which (new) energy is being absorbed and (previously) stored energy … Continue reading Energy Budget
EM Waves: Uses and Dangers
Different EM waves are used for different applications, which you are expected to be able to recall and explain. We will go through some of these uses in this article, which is unavoidably long as there is a lot of information to cover. Your exam preparation should therefore involve making summary notes from the wealth … Continue reading EM Waves: Uses and Dangers
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