Hans Geiger and Ernest Marsden Scattering Experiment

 Hans Geiger and Ernest Marsden were two of the pioneers in the field of atomic physics. Their work on the scattering of alpha particles by a thin gold foil, which was conducted in 1909 under the supervision of physicist Ernest Rutherford, played a crucial role in the development of the modern theory of the structure of the atom.

Geiger and Marsden's experiment involved shooting a beam of alpha particles (positively charged particles consisting of two protons and two neutrons) at a thin gold foil. They expected the alpha particles to pass straight through the foil, but to their surprise, some of the particles were scattered at large angles. This result indicated that there must be a dense, positively charged nucleus at the centre of the atom, surrounded by electrons.

Lord Ernest Rutherford used these results to develop his famous model of the atom, in which the nucleus is depicted as a small, dense, positively charged core surrounded by a cloud of electrons. This model, which is now known as the Rutherford Nuclear model, was a major advancement in our understanding of the structure of matter and laid the foundation for much of the research in atomic physics that has taken place since.

Youngs Modulus

 One of the hardest parts of working out Youngs Modulus is working out how to read a vernier scale correctly. Needed for the thickness of the wires and the change in length.

Objective:

• To measure the Young's modulus of a piece of wire using a tensile test.

Materials:

• Piece of wire
• Tensile testing machine
• Ruler or caliper for measuring the length and diameter of the wire
• Graph paper

Procedure:

1. Cut a piece of wire to a specific length (e.g., 20 cm) and measure its diameter using a ruler or caliper. Record the length and diameter in a data table.

2. Attach the wire to the tensile testing machine and set it to apply a tensile force at a constant rate.

3. Measure the deformation (e.g., elongation) of the wire as the tensile force is applied. Record the stress (i.e., the applied force divided by the initial cross-sectional area of the wire) and strain (i.e., the deformation divided by the initial length of the wire) in the data table.

4. Repeat the tensile test at least three times with different loads (e.g., 50 N, 100 N, 150 N).

5. Plot the stress versus strain on a graph using graph paper.

6. Determine the slope of the linear portion of the curve, which is the Young's modulus of the wire.

7. Calculate the average Young's modulus of the wire based on the results of the multiple tests.

Discussion:

• Discuss the importance of Young's modulus in engineering applications.
• Compare the Young's modulus of the wire with that of other materials (e.g., steel, aluminum, wood).
• Discuss factors that may affect the Young's modulus of a material, such as temperature and humidity.

Assessment:

• Have students write a lab report summarizing the procedure, results, and discussion of the experiment.
• Have students present their findings in a class discussion or presentation.
• Have students answer questions about the experiment and the concept of Young's modulus in a quiz or exam.
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• Young's modulus, also known as the elastic modulus, is a measure of the stiffness of a solid material. It is defined as the ratio of the applied stress to the corresponding strain in the material. Young's modulus is a measure of the stiffness of an object, and is calculated by dividing the applied stress by the resulting strain. It is typically measured in units of pascals (Pa) or gigapascals (GPa). The higher the Young's modulus, the stiffer the material is. Some common materials and their Young's moduli are:

  • Steel: 200 GPa
  • Aluminum: 70 GPa
  • Concrete: 25 GPa
  • Wood: 12 GPa
  • Rubber: 0.01 GPa

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.