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Thermometer

Theme B - The Particulate Nature Of Matter

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Rocket

Theme A - Space, Time & Motion

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Water Wave

Theme C - Wave Behaviour 

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Magnifying Glass Tilted Right

Theme D - Fields

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Microscope

Theme E - Nuclear & Quantum Physics

<ul>
	<li>Think of it as &quot;Energy Balance of a System.&quot;</li>
	<li>The system&#39;s energy can change if:
	<ul>
		<li>Work is done by it or on it.</li>
		<li>There are temperature differences between the system and its surroundings.</li>
	</ul>
	</li>
</ul>

<ul>
	<li>For IB Diploma: Q = &Delta;U + W
	<ul>
		<li>Q = energy transferred</li>
		<li>&Delta;U = change in system&#39;s internal energy</li>
		<li>W = work done by the system</li>
	</ul>
	</li>
</ul>

🎈 Real-World Example: Imagine a balloon. If you heat it (Q is positive), it expands and does work to push the surrounding air out of the way (W is positive). If the balloon&rsquo;s air heats up too, its internal energy rises (&Delta;U is positive).

<ul>
	<li>Clausius (For IB):
	<ul>
		<li>+Q = Heat goes from surroundings to the system</li>
		<li>+&Delta;U = System&#39;s energy increases</li>
		<li>+W = System does work on surroundings</li>
	</ul>
	</li>
	<li>IUPAC Convention (Be aware!): &Delta;U = Q + W
	<ul>
		<li>Different signs for work, but don&#39;t get tricked - both lead to the same answers.</li>
	</ul>
	</li>
</ul>

🍳 Example: Cooking an egg. The pan gets hot (Q from stove to pan is positive), the pan&#39;s energy increases as it heats up (+&Delta;U), and it cooks the egg by doing work on it (+W).

<ul>
	<li>80J to a System
	<ul>
		<li>W = -80J (work is done by surroundings on the system)</li>
		<li>&Delta;U = +60J (energy of the system increases)</li>
		<li>Q = -20J (energy moves from the system to the surroundings)</li>
	</ul>
	</li>
	<li>Gas Expands Without Temperature Change
	<ul>
		<li>Why? When the gas expands, it does work on the surroundings (positive W). So, it needs to get energy from somewhere - that&rsquo;s Q. And because temperature doesn&#39;t change, &Delta;U = 0.</li>
	</ul>
	</li>
</ul>

🎈 Fun Fact: It&#39;s like when you blow up a balloon. The air inside is doing work to stretch the balloon. But if the air inside the balloon doesn&rsquo;t cool down, it means it got some energy (maybe from your breath) to compensate.

<ul>
	<li>Cylinder, Piston, and Gas</li>
	<li>Change in energy, &Delta;U = 7.0J</li>
	<li>Temperature rise, &Delta;T = 22K</li>
</ul>

🍵 Example: Boiling water. As you heat the water (positive Q), it gets warmer (positive &Delta;U). If you heat it enough, it boils and pushes the air above it, doing work (positive W).

<ul>
	<li>Energy balance for compressed gas?</li>
	<li>Fixed volume gas, energy added - what&#39;s the change?</li>
	<li>Gas compressed, temperature rises, no energy exchange - how much work was done?</li>
	<li>Compressed gas in a cylinder - energy change and transfer?</li>
</ul>

🤓 Remember! Always keep track of signs and be consistent with the convention. Just like deciding whether going up or down is positive when you&rsquo;re studying things that move, the same consistency matters here.

&nbsp;

🌍 Wrap-Up: Thermodynamics is about energy changes. Systems do work, get or lose energy, and these changes follow predictable rules. Like a bank account, but for energy! Keep practicing, and soon, this will be a piece of (thermodynamic) cake for you! 🍰

Theme B - The Particulate Nature Of Matter

Unlocking The First Law of Thermodynamics: Insights & Examples

Table of content

Main idea - first law of thermodynamics

Math time - the formula

Signs matter - clausius convention vs IUPAC convention

Unlock the Full Content!

Theme B - The Particulate Nature Of Matter

Unlocking The First Law of Thermodynamics: Insights & Examples

Table of content

Main idea - first law of thermodynamics

Math time - the formula

Signs matter - clausius convention vs IUPAC convention

Unlock the Full Content!