Ways of doing the same experiment - Measuring the Speed of Sound

 I may do an experiment one way, but the exam papers may show the investigation another way. Getting the students to do the same experiments differently and compare all the results to find the most accurate. Round robins work well.  #ScientificMethod

One example of this is measuring the speed of sound.

1. Make a deafening sound and smoke simultaneously and have the students spread across the school field with arms up. as they hear the sound, they put their arms down. This a very effective demo, and knowing the distance and the time, the students can work out the speed of sound. The results are usually appalling, but it is a great demo to watch and participate in. This is great as an introduction.

2.

Using a tube and a tuning fork. This can be done in several ways - varying the tube length in water.

Resonance Tube Experiment:
a) Set up a long cylindrical tube vertically with a movable piston at the top. b) Adjust the position of the piston to create a resonant sound wave inside the tube. c) Measure the distance between the piston and the water level in the tube and the frequency of the sound produced.

d) Using the formula v = f * λ, where v is the speed of sound, f is the frequency, and λ is the wavelength, calculate the speed of sound.


Time of Flight Experiment:
a) Stand at one end of a long hallway or corridor and have another person stand at the opposite end. b) Use a stopwatch to measure the time it takes for a sharp sound, such as a clap or a pop, to travel from one end to the other.
c) Measure the distance between the two positions. d) Divide the distance by the time to obtain the average speed of sound.




Kundt's Tube Experiment:
a) Set up a transparent tube filled with fine talcum powder with a loudspeaker at one end. b) Generate a continuous sound wave using the loudspeaker.
c) Observe the formation of patterns or nodes in the powder as the sound wave travels through the tube. d) Measure the distance between consecutive nodes and calculate the wavelength.
e) Use the formula v = f * λ to determine the speed of sound, where v is the speed of sound, f is the frequency, and λ is the wavelength.

Getting the calculators ready for exams

Upgraded most of my A-level Maths student's fx-CG50 calculators to Version 3.8, ready for the exams. Not much new here, but is better for exam mode. Taught them how to set up exam mode as well.
 

MBPBC: Making a Mixing Bowl Ping-pong Ball Cyclotron

MBPBC: Mixing Bowl Ping-pong Ball Cyclotron 🌀 A mini LHC for your tabletop experiments! #SMBPBC #TabletopCyclotron #PhysicsFun

To create a Mixing Bowl Ping-pong Ball Cyclotron (MBPBC), follow these steps:

You will need

A large Mixing bowl. A transparent one is best

Some flat copper tape that is adhesive on one side

Some leads

A spare Van de Graaff generator

1) Take a ping-pong ball and cover it in graphite from a pencil

2) Create the charging strips

First make a cross from one side to the other. All the copper must make good contact with one another. These will be connected to one side of the Van de Graaff generator, say the +ve side

3) Now make another set of conducting strips. These must not touch the cross and must all be linked together. These form the -ve side. The copper wires therefore go -ve,+ve -ve +ve all around the mixing bowl, as in the picture below

4) Connect to the Van de Graaff Generator and put the ping  pong ball in, and switch on.

The ball will spring around the bowl

A different type of cyclotron

To create a Mixing Bowl Ping-pong Ball Cyclotron (MBPBC), follow these steps:

1. Materials:

   • A large, smooth mixing bowl
   • Ping-pong balls
   • Hairdryer or leaf blower
   • Optional: food colouring and water

2. Preparation:

   • Place the mixing bowl on a flat surface.
   • Optional: Add a thin layer of coloured water to the bowl's bottom to visualize the motion better.

3. Building the MBPBC:

   • Position the hairdryer or leaf blower with its nozzle pointing at a tangent to the bowl's inner surface near the rim.
   • Turn on the device at its lowest setting and gradually increase the speed until you see the desired circular motion.
   • Drop a ping-pong ball into the bowl, and observe how it accelerates around its inner surface, mimicking a cyclotron's particle acceleration.
   • Adjust the airspeed to maintain a stable circular motion of the ping-pong ball.

4. Experiment:

   • Try adding multiple balls, adjusting the airspeed, or tilting the bowl slightly to observe how these changes affect the motion.

Enjoy your homemade MBPBC! Remember, this is a simplified model for fun & educational purposes and doesn't replicate the exact functioning of a real cyclotron. #DIYPhysics #MBPBC #CyclotronFun

Centre of Mass

🔍 Finding a card's centre of mass: Suspend it with a hook in a small hole, use a plumb bob for balance, and watch it stand on a pencil tip! ⚖️📏✏️ #PhysicsFun #CenterOfMass

 

Exploring the central dogma

 Understanding how protein synthesis works from DNA through translation into mRNA to transcription into proteins using models to translate ATC into UAG into Isoleucine.

Understanding Protein Synthesis: From DNA to Proteins through Transcription and Translation

Protein synthesis is a complex, multi-step process that involves the conversion of genetic information stored in DNA into functional proteins. This process occurs through two main stages: transcription and translation. In order to gain a comprehensive understanding of protein synthesis, it is crucial to explore the molecular mechanisms underlying these stages, as well as the role of models in translating nucleotide sequences into amino acids.

1. DNA: The Genetic Blueprint

Deoxyribonucleic acid (DNA) is the genetic material present in the nucleus of cells, responsible for carrying the information required for an organism's development, functioning, and reproduction. DNA consists of a double helix structure composed of four nucleotide bases: adenine (A), thymine (T), cytosine (C), and guanine (G). The specific sequence of these bases constitutes the genetic code, which provides the blueprint for protein synthesis.

2. Transcription: From DNA to mRNA

The first step of protein synthesis is transcription, a process that converts the genetic information in DNA into a complementary messenger RNA (mRNA) molecule. During transcription, an enzyme called RNA polymerase binds to a specific region of the DNA, called the promoter, and unwinds the double helix. The RNA polymerase then synthesizes an mRNA molecule by matching the DNA's nucleotide bases with their corresponding RNA bases: adenine (A) pairs with uracil (U), thymine (T) pairs with adenine (A), cytosine (C) pairs with guanine (G), and guanine (G) pairs with cytosine (C).

3. Translation: From mRNA to Proteins

The second step of protein synthesis is translation, which occurs in cellular structures called ribosomes. During translation, the mRNA molecule is read in groups of three nucleotides, called codons, each corresponding to a specific amino acid. Transfer RNA (tRNA) molecules, carrying their respective amino acids, recognize and bind to these codons through their complementary anticodon sequences. The ribosome then facilitates the formation of peptide bonds between adjacent amino acids, creating a polypeptide chain. Once the entire mRNA molecule has been translated, the completed protein is released.

4. Decoding the Genetic Code: Translating ATC into UAG and Isoleucine

To better understand the translation process, it can be helpful to use models that illustrate the conversion of DNA sequences into amino acids. For example, consider the DNA sequence ATC. During transcription, this sequence would be converted into the mRNA codon UAG. However, it is essential to note that there was a mistake in the original statement, as UAG is a stop codon, which signals the end of the translation. The correct mRNA codon corresponding to the DNA sequence ATC is actually AUC, which codes for the amino acid isoleucine.

In conclusion, protein synthesis is a fascinating and intricate process that involves the conversion of the genetic information stored in DNA into functional proteins through transcription and translation. Understanding the molecular mechanisms underlying these stages and the role of models in translating nucleotide sequences into amino acids can help provide a clearer picture of this essential biological process.

Giving the Cyclotron a Whirl

🌀 Trying out a cyclotron! Made from a mixing bowl, copper tape & powered by a Van de Graaff generator⚡. The Ping-pong ball circled the bowl, but not too fast 🏓💨 #DIYcyclotron #sciencefun

 

Protest Vote

 I'm not answering this question because we didn't do or have demonstrated to us this required practical experiment is the answer I get when I go through exam papers in science with the students. the students just don't have the experience to answer