Energy Is Transferred Between Stores, Never Created

Lab Brief #1

🎯 Your mission

Set it up. Test it. Be amazed.

⚡ The twist

Speed isn't the same as force. Don't mix them up.

What you'll learn

Energy is conserved: every joule leaving one store arrives in another. A 0.5 kg ball dropped from 2 m transfers about 10 J from the gravitational store (E = mgh) into the kinetic store, and on landing that 10 J ends up in thermal stores and sound. Saying energy was 'lost' always means it was dissipated — spread into thermal stores so dilute that no useful work can be drawn from them. The total never changed; only its usefulness did.

Key words

energy store
A way energy is held in a system — kinetic, gravitational, thermal, elastic or chemical.
dissipation
The spreading of energy into thermal stores too dilute to do useful work, even though the total is unchanged.

Make a hypothesis first

Guess: where does the energy go?

Say your guess out loud — then find out if you were right.

Get ready

🧰 What you need

bouncy ball
metre rule
balance
phone camera

⚠️ Safety first

Bounce the ball away from windows and other people.

Step 1 of 4 · Read

Think about what you just learned: say what "energy store" and "dissipation" mean in your own words before you start.

Step 2 of 4 · Do

Drop a ball onto a hard floor from 1.0 m and record the height of each of the first four bounces. Calculate the gravitational store at each peak using E = mgh and work out what fraction was dissipated on each impact.

Step 3 of 4 · Observe

Record what actually happened, including anything that did not match what you expected.

Step 4 of 4 · Record

Write a conclusion that answers the question this lesson opened with, and state your uncertainty.

Question 1 of 3

A 0.5 kg ball is lifted 2 m. The gravitational store gains roughly:

How sure are you?😐 maybe

Question 2 of 3

When we say energy is 'lost' in a bounce, it has actually been:

How sure are you?😐 maybe

Question 3 of 3

Conservation of energy means that in any transfer:

How sure are you?😐 maybe

Mind = blown

🔥 A bolt of lightning is 5 times hotter than the surface of the sun.

Nice work!

You got 0 of 3 right.

Next: Kinetic Energy Rises with the Square of Speed All lessons

🎯

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✨ More to explore

🌍 Where you see this in real life: You use this every time you flip a light switch, ride a bike, or kick a ball.

🏆 Stretch challenge (try it this week): Time how long a small ball rolls down something, then change the slope and try again.

👨‍👩‍👧 For the dinner table: “Show me something at home that uses this kind of energy.”

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Energy Is Transferred Between Stores, Never Created

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Energy Is Transferred Between Stores, Never Created

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