Measuring Lift with an Airfoil – The Physics of Flight 

Why does a plane stay in the air? Students often know “it’s lift,” but not what lift is or how to measure it. That’s where our PASCO sensors make physics take off.

Introduction

Take a sheet of paper and place it under your bottom lip and blow. The paper will move from being limp to pointing horizontally. Lets investigate why.

🛠 The Setup

We use a small airfoil model mounted on a retort stand with a large fan in front of it suspended by a PASCO force sensor. By controlling the airflow speed and angle of attack, students can record real-time force measurements as the wing interacts with the moving air.

📊 The Science

As the air flows faster over the curved top surface of the wing than under it, a pressure difference develops. According to Bernoulli’s principle, this creates lift. But it’s not just theory – the sensors show the numbers live on screen.

Students can:

• Plot lift vs angle of attack to see how too steep an angle stalls the wing.

• Compare lift at different airspeeds and discover why planes need long runways.

• Calculate the lift coefficient (Cl) from their data, just like real aeronautical engineers.

🎓 Why It Works in Teaching

The beauty of PASCO’s system is that the data is immediate, accurate, and student-led. Instead of being told “wings create lift,” students watch the graphs build in front of them. They see how lift grows, peaks, and eventually falls away when the wing stalls.

It transforms a textbook diagram into a live experiment where students discover the physics of flight for themselves.

And the best bit? When they next get on a plane, they’ll know the maths and science that are keeping them in the sky.

 

Compound Interest, APR and Loans – Making Financial Maths Real

Ask any GCSE or A-Level Maths student what they’ll use maths for in the real world, and “compound interest” is usually top of the list. Whether it’s savings, loans, or credit cards, understanding how percentages build up over time is an essential life skill.

💷 Simple vs Compound Interest

• Simple interest is just adding the same amount each year.
  £100 at 5% simple interest for 3 years = £115.

• Compound interest is interest on interest.
  £100 at 5% compound interest for 3 years = £115.76.
  It doesn’t look much at first, but over decades the difference is huge.

What is APR and How Does It Work?

APR stands for Annual Percentage Rate – the true yearly cost of borrowing money. Unlike a simple “interest rate,” APR also includes extra charges such as fees, so it gives a fairer picture of what you’ll actually pay.

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💷 A Simple Example

Imagine you borrow £1,000 at 10% simple annual interest:

• After 1 year, you repay £1,100.

• That’s straightforward – interest is £100.

But most loans and credit cards don’t work that simply. They often charge interest monthly or even daily. That’s where APR helps us compare.

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📈 APR with Monthly Interest

Say a credit card charges 1.5% interest per month.
That sounds small – but watch what happens:

• After 1 month: £1,000 → £1,015

• After 12 months: £1,000 grows to about £1,195
  That’s nearly 20% extra in a year, not just 12 × 1.5% = 18%.
  This effect of interest on interest is called compounding.

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⚖ Why APR Matters

APR turns all this into one yearly percentage figure, so you can compare deals fairly.

• A personal loan might have an APR of 6%.

• A credit card might have an APR of 19.9%.

• A payday loan might quote “only 1% per day” – but that works out at over 3,600% APR!

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🎓 Teaching Tip

We use APR in class to show students:

• How a loan can cost far more than its headline rate suggests.

• Why repaying only the “minimum payment” on a credit card keeps debt hanging around for years.

• And why “0% interest” deals are worth double-checking for hidden fees.

APR takes the mystery out of borrowing and turns it into maths students can calculate, compare, and understand.

🏦 Loans and Repayments

Loans use the same maths but in reverse. Borrow £5,000 at 6% over 3 years, and you’ll pay back more than £5,000 – sometimes a lot more depending on the terms. Students are often shocked when they calculate how much that “cheap loan” actually costs over its lifetime.

🎓 Why We Teach It This Way

We use real examples:

• comparing two savings accounts,

• working out the total cost of a loan,

• or even checking how long it takes a credit card debt to vanish if you only pay the minimum.

It turns financial maths from abstract percentages into real decisions they (and their parents!) will one day face. And once students have run the numbers themselves, they’ll never look at an “interest-free” deal the same way again.

 

Lenz’s Law in Action: Induction Demonstrations for A-Level Physics

Lenz’s Law can feel abstract when students first meet it. The idea that “the induced current opposes the change that caused it” is a mouthful – but when you see it in action, it suddenly makes sense.

That’s why in our lab, we turn the law into a series of hands-on demonstrations:

🧲 The Falling Magnet in a Tube

Drop a magnet down a copper or aluminium tube and – instead of clattering out the bottom – it drifts slowly. The induced currents in the tube set up magnetic fields that oppose the falling magnet, creating a perfect, visible example of Lenz’s Law.

🔄 The Jumping Ring

Place a conducting ring on top of a solenoid, switch on the alternating current, and the ring leaps into the air. The changing magnetic flux induces a current in the ring, which creates its own magnetic field opposing the original – and off it goes.

⚡ Eddy Currents and Damped Motion

Swing a thick metal plate between the poles of a magnet and watch as it grinds to a halt. The eddy currents induced in the plate oppose the motion, converting kinetic energy into heat. Swap it for a slotted plate, and the effect nearly disappears – a brilliant visual contrast.

💡 Linking the Theory

Every demo highlights the same principle: the induced current always acts to oppose the change in flux. Whether slowing a fall, throwing a ring, or damping motion, Lenz’s Law ensures energy is conserved and systems resist sudden changes.

For students, seeing the law “fight back” in these dramatic ways makes induction far more than an equation in a textbook – it becomes a memorable, almost magical, part of physics.

 

The Digestive System – A Journey Through Our Knitted Guts

Let’s be honest – the digestive system is not the nicest thing to teach. The very thought of what goes on inside our guts is enough to make most students squirm. That’s why we have our knitted gut.

It’s life-size, soft, pleasant to touch, and best of all, it gives students a real sense of scale. I can pull out between 5–6 metres of small intestine from the model, and students can drape it around themselves to see just how much of it there is and where it all goes.

The journey starts with the tongue.
Students always protest: “My tongue isn’t that big!” Then they see the stomach and say: “My stomach isn’t that small!” – until I explain that, although small, it can expand to hold quite a bit.

Next, the students measure the liver. It’s surprisingly large, stretching right across the body. Nestled alongside is the pancreas, both of which are crucial to digestion.

• The liver does one job for digestion: it produces bile, which is carried by the bile duct.

• The stomach has two jobs: it produces pepsin (released first as pepsinogen) to start protein digestion, and it produces acid to kill off bacteria.

• The pancreas is a multitasker: it produces three enzymes – lipase to break down fats, carbohydrase for carbohydrates, and trypsin (made first as trypsinogen) to continue protein digestion.

From there, everything moves into the small intestine, with its villi to absorb nutrients, past the appendix, and into the large intestine, where water is absorbed. Finally, it travels through the rectum and out of the anus – cue the usual giggles.

The knitted gut turns what might be a repulsive topic into something students can see, touch, and laugh about – while still learning how remarkable their bodies really are.

 

Teaching Zimbardo’s Stanford Prison Experiment with Sensitivity

Few psychology studies capture students’ attention like Zimbardo’s Stanford Prison Experiment (1971). The setup is striking: ordinary students randomly assigned to be “guards” or “prisoners,” only for the roles to spiral into cruelty and suffering far quicker than anyone expected.

It’s a dramatic story, but also a challenging one. When teaching this study at GCSE or A-Level Psychology, it’s important to strike a balance between making it engaging and treating the subject with sensitivity.

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The Basics: What Happened

• A mock prison was created in the basement of Stanford University.

• Participants were randomly assigned to either a guard or prisoner role.

• Guards quickly became abusive, and prisoners became submissive or distressed.

• The study, planned for two weeks, was stopped after just six days.

Students find the setup fascinating, but it raises obvious ethical questions.

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Key Teaching Points

1. Situational vs Dispositional Factors
   The study highlights the power of situation — how roles and environment can influence behaviour — rather than individual personality.

2. Ethical Considerations

   • Lack of fully informed consent (participants couldn’t anticipate the level of distress).

   • Psychological harm (some prisoners experienced breakdowns).

   • The role of Zimbardo himself, who became too involved as “prison superintendent.”

3. Relevance Today
   Links to real-world examples (e.g., the Abu Ghraib prison scandal) demonstrate why the study remains important, even if it is now considered deeply flawed ethically.

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Teaching with Sensitivity

• Acknowledge distress: Make it clear that this was a real study with real emotional consequences.

• Keep it professional: Avoid over-dramatising or sensationalising.

• Encourage debate: Guide students to discuss what should have been done differently and what we can learn today.

• Provide perspective: Balance the “shock factor” with the psychology it teaches about conformity, obedience, and ethics.

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Classroom Activities

• Role-play light: Instead of re-enacting prison conditions, have students debate as an ethics committee reviewing Zimbardo’s study.

• Compare & contrast: Discuss how Zimbardo compares to Milgram’s obedience studies in terms of ethics and conclusions.

• Exam practice: Frame questions around evaluation — methodology, ethics, and situational vs dispositional explanations.

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✅ Teaching Zimbardo’s experiment is about more than retelling a dramatic study. Done sensitively, it helps students engage with psychology’s big questions: What drives human behaviour? How should we study it ethically? And what responsibility do psychologists have to their participants?

 

Demystifying Recursion: A Beginner’s Approach for GCSE Computer Science

For many GCSE Computer Science students, recursion feels like a magic trick. A function that calls itself? It sounds confusing, but once you break it down, recursion is simply another way of solving problems — often more elegant than loops.

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What Is Recursion?

Recursion is when a function solves a problem by calling itself with a smaller version of the same problem.

Every recursive function needs two parts:

1. Base case – the simplest version of the problem, where the function stops calling itself.

2. Recursive step – the part where the function calls itself with smaller input, moving closer to the base case.

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A Simple Example: Factorials

The factorial of a number n! means n × (n-1) × (n-2) … × 1.

We can write it recursively in Python:

def factorial(n):
    if n == 1:            # Base case
        return 1
    else:
        return n * factorial(n - 1)   # Recursive step

• factorial(1) returns 1 (the base case).

• factorial(4) becomes 4 × factorial(3), which becomes 3 × factorial(2), and so on… until the base case is reached.

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Why Use Recursion?

Some problems are naturally recursive — they involve breaking a problem into smaller versions of itself:

• Mathematics: factorials, powers, Fibonacci numbers.

• Computer Science: searching through file directories, tree structures, or solving puzzles like the Towers of Hanoi.

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Visualising the Process

One way to help students is to imagine recursion as a stack of plates:

• Each time the function calls itself, it puts a plate on the stack.

• When the base case is reached, the plates are removed one by one as the answers come back.

This “stack model” makes it easier to see how the function eventually unwinds to give the final answer.

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Teaching Tip

Start small. Get students to trace through factorial(3) on paper, writing down each call and return. Once they see the sequence, the “mystery” of recursion fades.

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✅ Recursion isn’t magic — it’s simply problem-solving by repetition, with a built-in exit plan. By tackling it step by step, GCSE students can turn confusion into confidence.

 

Le Chatelier’s Principle in Colour: Equilibrium Experiments That Speak for Themselves

Some chemistry experiments need a lot of explanation. This one doesn’t. When A-Level students investigate equilibrium using cobalt chloride, the chemistry literally changes colour in front of their eyes.

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The Experiment

We use the equilibrium between two forms of cobalt chloride:

$$[Co(H_2O)_6]^{2+} \;\;\; \rightleftharpoons \;\;\; [CoCl_4]^{2-} + 6H_2O$$

• The pink hexaaqua complex dominates in cold, dilute solutions.

• The blue tetrachlorocobaltate dominates when the solution is heated or concentrated with chloride ions.

In practice:

• A test tube of cobalt chloride solution is placed in cold water → it turns pink.

• The same tube in hot water shifts to blue.

• Adding hydrochloric acid pushes the equilibrium even further towards blue.

No lengthy explanation needed — the colours show the equilibrium shift.

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Linking to Le Chatelier’s Principle

Le Chatelier’s Principle states: If a system at equilibrium is disturbed, it will shift to oppose the change.

• Heat added (endothermic direction): The equilibrium shifts to favour the blue complex.

• Heat removed (exothermic direction): The equilibrium shifts to favour the pink complex.

• More chloride ions added: The equilibrium shifts right, producing more of the blue complex.

The colour changes give an immediate, visual confirmation of the principle.

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Why Students Remember This One

• It’s dramatic — the tube can go from pale pink to deep blue in seconds.

• It’s clear — no graphs needed to “prove” the shift.

• It’s extendable — students can design their own tests, like diluting or concentrating, to predict and check the outcome.

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Teaching Tip

Ask students to predict first: What will happen if I cool this? What if I add more chloride? Then run the experiment and let the colour answer. The simplicity means the principle lodges in memory.

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✅ Sometimes the best chemistry demonstrations are the ones that don’t need words. With cobalt chloride, Le Chatelier’s Principle speaks for itself — in pink and blue.