Models and real things

The model lungs show us how the lungs work, but they are only a model and no substitute for looking at the real thing. Investigating the diaphragm and inflating the lungs of a sheep. The lungs are a pair of spongy, air-filled organs that are located on either side of the chest (thorax). The trachea (windpipe) carries air from the mouth and nose into the lungs through a series of tubes called bronchi. The bronchi branch off into smaller and smaller tubes called bronchioles, which end in clusters of tiny round air sacs called alveoli.

When you inhale, the diaphragm (a muscle located at the base of the lungs) contracts and moves downward, creating more space in the chest cavity. This increases the volume of the chest cavity and decreases the pressure inside it. As a result, air is drawn into the lungs through the trachea, bronchi, and bronchioles.

The air that enters the lungs is warm and moistened by the nose and tubes. It then passes through the alveoli, where oxygen and carbon dioxide exchange occurs. Oxygen from the air diffuses across the thin walls of the alveoli and into the blood vessels called capillaries that surround them. At the same time, carbon dioxide, a waste product of the body's cells, diffuses from the blood into the alveoli to be exhaled.

When you exhale, the diaphragm relaxes and moves upward, decreasing the volume of the chest cavity and increasing the pressure inside it. This forces the air out of the lungs through the trachea, bronchi, and bronchioles.

The lungs are essential for breathing and play a vital role in the body's respiratory system. They help to oxygenate the blood and remove waste products, such as carbon dioxide, from the body.

A Level Physics Topic by Topic | Hooke's law of Elasticity and Inelastic Materials

Hooke's law is an important concept in many fields, including engineering, where it is used to design and analyze systems such as suspension systems in vehicles and the springs in mechanical clocks. It is also used in studying the behaviour of materials under stress and in designing structures and machines that rely on the elastic properties of materials.or compress a spring is directly proportional to the displacement or deformation of the spring. In other words, the greater the force applied to a spring, the greater the displacement or deformation of the spring will be.

When two or more springs are connected in series, the total force required to stretch or compress all of the springs is equal to the sum of the forces required to stretch or compress each spring individually. The total displacement or deformation of the series of springs is equal to the displacement or deformation of the first spring plus the displacement or deformation of the second spring, and so on.

When two or more springs are connected in parallel, the total force required to stretch or compress all of the springs is equal to the force required to stretch or compress a single spring with the same spring constant as the parallel combination. The total displacement or deformation of the parallel springs is equal to the displacement or deformation of any one of the springs.

Hooke's law is an important concept in many fields, including engineering, where it is used to design and analyze systems such as suspension systems in vehicles and the springs in mechanical clocks. It is also used in studying the behaviour of materials under stress and in designing structures and machines that rely on the elastic properties of materials.

Better Titration

 The @Pascoscientific drop counter. It does titrations really fast and accurately so this is ideal for revision ( some mock exams coming up) and produces great data for lots of calculation practice 

First Analog Computing Lesson

Analog computers can be implemented using various hardware components, including resistors, capacitors, inductors, and operational amplifiers. These components can be used to build circuits that perform mathematical operations, such as addition, subtraction, multiplication, and division. The Lesson Plan can be found at Analog computing

Proof by contradiction

 Proof by contradiction, also known as indirect proof or reductio ad absurdum, is a method of proof in which a claim is shown to be true by showing that the opposite of the claim leads to a contradiction or absurdity.

Experimenting with spintronics

 

Time to play and experiment with spintonics from @UpperStoryCo and write some lesson plans for it. Discovering it is not only good for electronics but its quite good for mechanics and problem solving as well.

Resistivity

The resistance of a wire is directly proportional to its length. This means that as the length of a wire increases, its resistance also increases. This relationship can be described by the equation:

R = ρL / A

where R is the resistance of the wire, ρ is the resistivity of the material, L is the length of the wire, and A is the cross-sectional area of the wire.

The reason for this relationship is that as the length of a wire increases, the number of collisions between the electrons and the atoms of the wire also increases. These collisions cause resistance and make it more difficult for the electrons to flow through the wire. As a result, the resistance of the wire increases as its length increases.

It's important to note that this relationship holds true only for a given material and cross-sectional area. If the material or cross-sectional area of the wire is changed, the relationship between length and resistance will also change.

Resistivity is a measure of the resistance of a material to the flow of electric current. It is typically denoted by the symbol ρ and is expressed in units of ohm-meters (Ω*m).

In general, materials that are good conductors of electricity have low resistivity, while materials that are poor conductors have high resistivity. For example, metals such as copper and aluminium have low resistivity and are commonly used in electrical wiring because they allow an electric current to flow easily. On the other hand, materials such as rubber and glass have high resistivity and are often used as insulation because they resist the flow of electric current.

The resistivity of a material is related to its electrical conductivity, which measures how easily a material allows electric current to flow. The relationship between resistivity and conductivity is given by the equation:

conductivity = 1 / resistivity

This means that materials with high resistivity have low conductivity and vice versa.