There is a separate article that explains magnetic fields and forces so this article focuses on magnetic materials and the difference between permanent and induced magnets. There are naturally occuring rocks that are capable of being magnetised (magnetite) and others that are already magnetised (lodestone). The important ingredient in both of these rocks is iron … Continue reading Permanent and Induced Magnetism
Contact and Non-Contact Forces
It is surprisingly hard to say what a force really is but on a simple level we say that forces are either pushes or pulls. It would be better to label "pulls" as forces of attraction and "pushes" as forces of repulsion. Some forces have their effect when objects are in contact whereas others allow … Continue reading Contact and Non-Contact Forces
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
Resolving Vectors
Having covered the basics of resultant forces, we can progress to a method for analysing vectors that does not rely purely on scale drawings. Before proceeding, let me stress that this approach is not needed for GCSE Physics but the method should be accessible to mathematically inclined readers and will prove very useful in post-GCSE … Continue reading Resolving Vectors
Resultant Forces (part 3)
In the final part of this mini-series, we have to deal with situations where the two component forces are neither opposite nor at right angles; the forces are simply at some general angle to each other. Typical situations where this could apply in real life are tugs pulling a ship or an airplane flying through … Continue reading Resultant Forces (part 3)
Resultant Forces (part 2)
In the first part of this mini-series we looked at forces that act in exactly opposite directions. We noted that although these forces can be subtracted, the correct procedure is to combine the forces in more rigorous way that clearly takes account of both their magnitude and their direction. The most powerful way to do … Continue reading Resultant Forces (part 2)
Resultant Forces (part 1)
The principle of resultants states that when two or more forces act on an object, they can be replaced with a single force that has the same effect as the multiple forces combined. This is a fairly simple idea but putting it into practice can produce a lot of confusion so let’s start with a … Continue reading Resultant Forces (part 1)
Determination of ‘little-g’
One of my favourite experiments in GCSE physics is a practical that seems to have fallen from favour in recent years – but it’s still worth exploring. The experiment involves using a ticker-timer to make dots at regular time intervals (0.02 s apart) on a strip of tape that is attached to a moving object. … Continue reading Determination of ‘little-g’
Molar Heat Capacity
There is a required practical in GCSE Physics courses, including Trilogy, that involves calculating the specific heat capacity of different metal blocks. This is done by measuring the energy supplied (using voltage, current and time) and monitoring the temperature increase. You are expected to recall this experiment and be able to suggest how it could … Continue reading Molar Heat Capacity
Magnificent moles
You may well ask, what is the point of an SI unit that measures “amount”? Surely if we want to know an amount then we simply count whatever it is that we need to quantify. That’s fine until we get to VERY large numbers. How large? We’re talking here about numbers that are massively bigger … Continue reading Magnificent moles
Mr Tarrant's physbang 'blog 