Three years ago I explained how to use photographs to estimate the speed of a passing car. You can read that article at https://physbang.com/2020/08/02/keep-the-cogs-turning/. Now it is time to use a similar technique to answer a more challenging question: what is the take-off velocity of a passenger jet? Of course, the answer could be found … Continue reading Aircraft take-off velocity
Motion Along a Line
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
Acceleration and Distance
To find acceleration without measuring time, we can use a combination of the object's mean speed and distance-moved as a substitute for time. We already know that speed is calculated as distance divided by time, so we can rearrange this equation to calculate time as distance divided by speed. Of course, the speed of an … Continue reading Acceleration and Distance
Measuring Speed
This is the third part of a mini-series looking at motion and here we’ll be considering different ways to measure speed as well as some common sources of error. In theory, speed is easy; we just need a distance (measured using a ruler, for example) and a time (probably measured using a stopwatch but ideally … Continue reading Measuring Speed
Speed and Acceleration
When a stationary object starts moving in a straight line, its motion can be divided into two stages. The first stage is when the speed of the object is increasing; the second stage is when the object has reached a steady speed. We can rephrase these two stages using the word acceleration; the first stage … Continue reading Speed and Acceleration
Squirrel speed
How fast can a squirrel run? I'm talking here about a red squirrel (the type we have in Jersey) and I'm assuming that the creature has been startled and is dashing for cover. Think for a moment: what sort of experiment could you arrange to answer this question? At its simplest, this is a time-and-distance … Continue reading Squirrel speed
Interpreting graphs
Graphs are a great way of presenting information in a format that is easy to understand but it's important you can describe them accurately as this skill is commonly tested in GCSE Physics papers and it ought to be an easy way to accumulate marks. I recommend a three-step approach, as outlined below. 1. Always … Continue reading Interpreting graphs
Keep the cogs turning!
The phenomenon of "learning loss" during the long summer holidays is well known so to keep your physics cogs turning, here's a brief challenge. I took my camera to the Five Mile Road on Saturday and photographed cars going past. The camera was set to 5fps so every sixth picture should have been recorded exactly … Continue reading Keep the cogs turning!
Speed – A Crash Course
In view of the current school closure, this post has been created to summarise the learning steps that you have already followed to gain a firm understanding of speed in terms of distance and time. You should work through this page to check and improve your knowledge. The key learning outcomes are; The units of … Continue reading Speed – A Crash Course
Work Done and GPE
The basics of energy stores and transfers are covered in a separate post (click here to refresh your memory if necessary). We now need to think specifically about ways in which energy can be transferred by the action of forces. For the purposes of GCSE Physics, we will restrict our thoughts to mechanical forces but … Continue reading Work Done and GPE