The velocity of a wave

#FunFact: You can determine the velocity of a wave in 2 ways! Use your phone's SloMo to measure distance and time OR use the wavelength and frequency relationship. Bonus: compare circular and straight wave speeds! #Physics #WaveVelocity

1. To determine the velocity of a wave, you can use the slow-motion (SloMo) feature on your phone's camera to measure the time it takes for a wave to travel a known distance. By dividing the distance traveled by the time it took to travel, you can calculate the velocity of the wave.

2. Another way to determine the velocity of a wave is to use the relationship between its wavelength and frequency. The velocity of a wave is equal to the product of its wavelength and frequency. By measuring the wavelength and frequency of a wave, you can calculate its velocity. Additionally, you can compare the velocities of circular and straight waves to determine any differences in their speeds.

 

Blood Tests

Blood types matter! 🔬🩸 Students use the Carolina Pack to determine their blood type - A, B, AB, or O - and whether they're Rhesus positive. It's all about antigen tests with fake blood. #science #education #biology

Blood Types: Understanding the Basics

Blood is a vital component of our bodies, carrying oxygen and nutrients to all of our organs and tissues. But did you know that not all blood is the same? Blood types play an important role in transfusions, organ donations, and even in our health. This article will explore the basics of blood types and what they mean.

The ABO Blood Group System

The ABO blood group system is the most well-known and widely used blood typing system. It classifies blood into four types: A, B, AB, and O. These classifications are based on the presence or absence of antigens on the surface of red blood cells.

Type A blood has the A antigen on its surface, while type B blood has the B antigen. Type AB blood has both A and B antigens, and type O blood has neither A nor B antigens. The presence or absence of these antigens determines which blood types can be safely transfused.

For example, type A blood can be safely transfused to individuals with type A or AB blood, but not to those with type B or O blood. Similarly, type B blood can be safely transfused to individuals with type B or AB blood, but not to those with type A or O blood. Type AB blood can be safely transfused to individuals with any blood type, while type O blood can only be safely transfused to individuals with type O blood.

The Rh Factor

Another important component of blood typing is the Rh factor. This refers to the presence or absence of a particular antigen, the D antigen, on the surface of red blood cells. If you have the D antigen, you are Rh-positive. If you don't have the D antigen, you are Rh-negative.

The Rh factor is particularly important for pregnant women. If a woman who is Rh-negative becomes pregnant with a Rh-positive baby, there is a risk that her body will produce antibodies against the Rh antigen. This can lead to hemolytic disease of the newborn, a condition in which the baby's red blood cells are destroyed by the mother's antibodies. To prevent this, Rh-negative women are given a medication called Rh immune globulin during pregnancy.

Determining Your Blood Type

Blood typing is usually done through a simple blood test. A small amount of blood is collected and mixed with antibodies that react with specific antigens. Based on the reactions, the blood type is determined.

In some cases, blood typing may be done using a kit like the Carolina Pack, which uses fake blood to simulate blood typing. This can be a useful tool for educational purposes or for individuals who may not have access to a laboratory for blood testing.

Conclusion

Blood types play an important role in our health and medical care. Understanding your blood type can help you make informed decisions about blood transfusions, organ donations, and other medical procedures. If you don't know your blood type, talk to your healthcare provider about getting tested.

Maths worked examples.

Why do math examples for students leave out crucial steps? It's helpful to show how to solve problems when students get stuck, but omitting important stages leaves them still stuck. #matheducation #learningmath #teachingmath

Let there be Light

The human eye can be deceptive in judging light levels, as we can see in both dark and bright conditions. However, using the @Pascoscientific Light sensor revealed surprising actual figures to students. #LightSensor #ScienceEducation

DNA Extraction

DNA Extraction from Strawberries is fun and can be done at home with just one special ingredient, extremely cold isopropyl alcohol. It's a great fun experiment to do.

Extracting DNA from strawberries is a fun and simple experiment that can be done at home using household items. Here's a step-by-step guide:

Materials:

• Fresh strawberries
• Ziploc bag
• Table salt Sea salt is best
• Dish soap or washing up liquid
• Water
• Meat tenderizer (optional)
• Kitchen Roll for the filter
• Rubbing alcohol (or its proper name Propan-2-ol or isopropyl alcohol)
• Small glass or plastic cup
• Wooden stick or skewer

Procedure:

1. Start by placing a few strawberries in a Ziploc bag and mashing them with your hands or a rolling pin until they are completely squished.
2. Put some isopropyl alcohol in the freezer. (Don't worry it will not freeze.)
3. Mix 1/4 teaspoon of table salt, 1 tablespoon (20ml) of washing up, and 1/2 cup of water in a separate cup. Stir the solution gently to avoid creating too many bubbles.
4. Pour the salt and soap solution into the Ziploc bag with the mashed strawberries and gently mix the contents together for about 5 minutes.
5. Add a pinch of meat tenderizer to the bag and continue to mix gently for another 2-3 minutes. The meat tenderizer helps break down the cells' proteins and release the DNA.
6. Place a coffee filter or kitchen roll over a clean cup and pour the bag's contents onto the filter. Let the mixture drain through the filter, and use a wooden stick or skewer to push the pulp through the filter to extract as much liquid as possible. This bit takes a long time.
7. Carefully pour about 2-3cm or 1 inch of rubbing alcohol into the cup, and carefully pour the strawberry mixture onto the surface of the alcohol. Do not mix the alcohol and strawberry mixture; you should see a clear separation of the two liquids.
8. Wait for a few minutes, and you should start to see white, stringy strands appear at the boundary between the alcohol and the strawberry mixture. These strands are the DNA! You can use a wooden stick or skewer to gently scoop out the DNA strands and examine them more closely.

Note: This experiment involves the use of rubbing alcohol, which can be dangerous if ingested or inhaled. Make sure to perform the experiment in a well-ventilated area, and avoid getting rubbing alcohol on your skin or in your eyes.

Flywheels and Gyros

Angular momentum is a property of an object in motion that depends on its mass, velocity, and distance from the axis of rotation. Students seem to find the concepts counterintuitive and almost magic.

 When an object rotates around an axis, it has angular momentum in the direction perpendicular to the plane of rotation.

In a gyro, a spinning rotor is mounted in a set of gimbals, which allow it to rotate freely in any direction. When the gyro is moved or rotated, the rotor resists the change in direction due to its angular momentum, causing the gimbals to move in a way that reflects the change in direction. This resistance to change in direction is known as gyroscopic stability.

Gyroscopes are commonly used in navigation systems, aircraft, and spacecraft to measure orientation and angular velocity. They are also used in stabilizing cameras, drones, and other equipment that needs to maintain a steady position in space.

Flywheels are often used as a form of energy storage because they can store energy in the form of rotational kinetic energy. This energy can be released quickly and efficiently when needed, making flywheels useful for various applications.

One of the most common applications of flywheels for energy storage is in electric or hybrid vehicles. When the vehicle is braking, the energy is used to spin up a flywheel, storing the energy as rotational kinetic energy. Later, when the vehicle needs to accelerate, the energy can be drawn from the flywheel, converting the kinetic energy back into electrical energy to power the vehicle's electric motor.

Flywheels can also be used to store energy in renewable energy systems, such as wind or solar power. The energy generated by wind turbines or solar panels can be used to spin up a flywheel, storing the energy until it is needed. This energy can be released quickly and efficiently, providing a reliable power source even when the wind is not blowing, or the sun is not shining.

Another application of flywheels for energy storage is grid stabilization. Fluctuations in power supply and demand can cause instability in the electrical grid, and flywheels can be used to smooth out these fluctuations by providing a buffer of stored energy that can be quickly released when needed.

Electrolysis Required Practical

Electrolysis Required Practical: When discussing electrolysis with a student who had not previously performed the experiment, observed a demonstration or watched a video on the topic, I instructed them to set up and conduct the practical on their own.