Having looked at the first Physics paper for this year's AQA Trilogy examination, it seems to me that a significant proportion of questions have been framed around situations and applications rather than just recalling and connecting facts. With that in mind, let's take a real-world look at motion along a line... First an important definition. … Continue reading Motion Along a Line
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’
Slowing and Stopping
To conclude the recent series of posts related to different aspects of motion, we will now look at a real-world application of these ideas: in particular, the physics of slowing and stopping a road vehicle. An earlier post (from 2019) covered the two components of a vehicle’s overall stopping distance so I won’t repeat that … Continue reading Slowing and Stopping
Momentum
Newton's Second Law of Motion tells us that the force required to accelerate an object can be calculated by multiplying the mass of the object by the acceleration that is required (F=ma). We also know that acceleration is simply the rate of change of velocity (the change in velocity divided by the time taken for … Continue reading Momentum
Force and Acceleration
There are various techniques that can be used to investigate the relationship between force, mass and acceleration (Newton’s Second Law of Motion). In a school lab, we often use a dynamics trolley (wheeled platform) that is attached to a mass hanger via a string that runs over a desk pulley. The mass hanger provides the … Continue reading Force and Acceleration
Forces and Motion
Let’s get the common misconception out of the way first: moving objects do not remain in motion because there is a force that keeps them going. In fact, it’s the opposite. Moving objects always remain in the same state of motion unless an external force stops them. By “the same state of motion” we mean … Continue reading Forces and Motion