Mass is a tricky concept. We all think we know what it is: it's what you measure when you put something on weighing scales or a digital balance. Alternatively, you could say mass is the property of an object that resists changes to its movement. In other words, an object with lots of mass is … Continue reading What is mass?
Key Facts: Electric circuits
Electricity is one of the forms of energy transfer so it is not surprising that the definition of the volt (the unit for measuring potential difference) is the energy carried per unit charge. In symbols, where Q is the symbol for charge, this relationship is written as; V = E / Q It is important … Continue reading Key Facts: Electric circuits
Key Facts: Waves
We can define a wave as something that carries energy from one place to another without the transfer of physical matter. To understand this definition it is useful to think about two different ways of feeling heat. In a shower, heat is created by an energy exchange inside the storage tank or shower unit and … Continue reading Key Facts: Waves
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
Non-binary electrons
On the final day of term, a member of my form tested me with a series of science jokes, the first of which was; “Why does a beef burger have less energy than a steak?” Pause here if you want to come up with your own solution. I must admit that I didn’t guess the … Continue reading Non-binary electrons
Phase-change diagrams
The concepts of specific heat capacity and specific latent heat are nicely illustrated in phase-change diagrams. But how realistic are the diagrams that are commonly seen online? The answer, perhaps surprisingly, is "not very". The phase-change diagram shown below is useful in terms of the amount of information it provides but, in common with many … Continue reading Phase-change diagrams
Absolute Zero
Where does the idea of "absolute zero" come from? In part it stems from a need to avoid negative temperatures but a better explanation can be found by thinking about the kinetic theory of gases. When a gas is heated, its particles gain kinetic energy. This in turn means that the particles have a higher … Continue reading Absolute Zero
Mr Tarrant's physbang 'blog 