Most people say you shouldn't go out on a summer's day wearing black because you will get too hot. It would be much better to wear white as this will keep you cooler. But is that actually true? We can test this idea using two boiling tubes that have been sprayed to have different surface … Continue reading Surface Colour and Heating
Thermal Equilibrium
Any object that has a constant temperature is in a state of thermal equilibrium. This means the rate at which energy is transferred to the object is exactly equal to the rate at which energy is transferred from the object. In the context of electromagnetic radiation, we can state that the rate at which the … Continue reading Thermal Equilibrium
Uses and Dangers of EM Waves
Electromagnetic (EM) waves are all similar; they are all transverse waves that travel at the same velocity and are created by the movement of electrons. But they are also different, not only in wavelength and frequency but also in how they are reflected, absorbed or transmitted by different materials. For example, the microwaves that your … Continue reading Uses and Dangers of EM Waves
All about Springs
The facts and understanding that you need to have about springs is less detailed than it is for some other GCSE Physics courses. It is therefore important to use learning resources that are matched to this particular course. If you start reading about ultimate tensile stress, for example, then you are learning too much! The … Continue reading All about Springs
Calculating KE & GPE
By the end of your GCSE Physics course you will be able to calculate four different types of energy; kinetic, gravitational, electrical and strain. At this stage, however, we will limit ourselves to the first two. Kinetic energy (KE) is the energy that is stored by moving objects. We are only interested in objects that … Continue reading Calculating KE & GPE
Voltage and Current
When you first started learning about circuits, either in primary school or in Y7, you should have been told about voltage and current. These two measurements were probably presented as separate ideas but in fact they both relate to one thing; electrical charge. Voltage relates to the amount of energy given to the charge that … Continue reading Voltage and Current
Stopping Distance
The exam board appears to be very keen on aspects of physics that relate to real life - and vehicle stopping distance is an excellent example. You should therefore ensure that you are confident about this topic as there are standard "right" answers that you need to know. Stopping distances are divided into two parts. … Continue reading Stopping Distance
Levers and Gears
We have covered the theory of work done so now it’s time to look at some simple machines that trade force against distance to make tasks easier than they would otherwise be. In this post we will look at levers and gears, which "magnify" forces by moving a smaller force through a larger distance. This … Continue reading Levers and Gears
Energy is not Power!
Suppose that two identical twins decide to go upstairs in their house: one twin runs up the stairs whereas the other twin walks up the stairs. Which twin transfers the greatest amount of energy? Almost everybody says the twin who runs transfers more energy because she goes faster. This is a common misconception. In fact, … Continue reading Energy is not Power!
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