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Water Wave

Theme C - Wave Behaviour 

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Rocket

Theme A - Space, Time & Motion

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Thermometer

Theme B - The Particulate Nature Of Matter

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Magnifying Glass Tilted Right

Theme D - Fields

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Microscope

Theme E - Nuclear & Quantum Physics

<ul>
	<li>
	Definition: It predicts how waves bend when they pass from one medium to another.
	</li>
	<li>
	Formula: \(\frac {v1}{v2} = \frac {sinθ1}{sinθ2}\)

	<ul>
		<li>v1 and v2 = Wave speeds in medium 1 and 2.</li>
		<li>&theta;1 and &theta;2 = Angles between rays and normal to the boundary.</li>
	</ul>
	</li>
	<li>
	Did You Know? It was named after Snellius, but he wasn&#39;t the first to discover it. Ibn Sahl talked about it around 1000 CE.
	</li>
</ul>

<ul>
	<li>Speed of light in a vacuum = c</li>
	<li>Formula: 2sin&theta;2\(\frac {sinθ \ vacuum}{sinθ2} = \frac {c}{v2}\)​​</li>
	<li>Refractive Index (n): n = \(\frac {c}{v2}\). This gives the slowing factor of light in a medium.
	<ul>
		<li>It doesn&#39;t have a unit!</li>
		<li>Always &gt; 1 when light moves from vacuum to another medium.</li>
	</ul>
	</li>
</ul>

Formula Twist: Using the refractive index, Snell&#39;s Law can be expressed as: \(\frac {sinθ1}{sinθ2} =\frac {n2}{n1}\)

<ul>
	<li>What&rsquo;s Happening? Light energy makes electrons in materials vibrate. Unless the light&#39;s frequency matches a material&#39;s &quot;natural frequency,&quot; the energy is re-emitted but after a delay.
	<ul>
		<li>Real-world Analogy: Think of it like passing a message in a game of &quot;Telephone&quot;. The message (light) gets slightly altered (slowed) as each person (material) takes a moment to understand and then pass it on.</li>
	</ul>
	</li>
	<li>More atoms in a material = Slower light travels through it.</li>
</ul>

Huygens had diagrams and ideas about refraction. But people believed Newton&#39;s different theory because, well, he was Newton! Only later did they realize Huygens was onto something!

Tools Needed

<ul>
	<li>Know how to measure angles precisely.</li>
	<li>Do calculations with fractions and trig ratios.</li>
	<li>Record measurement uncertainties.</li>
</ul>

Steps

<ul>
	<li>Use a semicircular transparent block (like glass or Perspex).</li>
	<li>Draw around it on paper, mark its center.</li>
	<li>Shine a light beam through its center.</li>
	<li>Mark where the light goes, measure the angles.</li>
	<li>Calculate the refractive index from the data. Remember uncertainties!</li>
</ul>

<ul>
	<li>Example 1: Light Hits Glass
	<ul>
		<li>Problem: Light in air strikes glass at 65&deg;. If the glass has a refractive index of 1.48, what&#39;s the angle inside the glass and the light&#39;s new wavelength?</li>
		<li>Answer: The angle is 37.8&deg;, and the new wavelength is 359nm.</li>
	</ul>
	</li>
	<li>Example 2: Waves at the Beach!
	<ul>
		<li>Problem: Sea waves move from shallow to deep water. What happens?</li>
		<li>Answer: Waves go faster in the deep water (7.3ms&minus;1&nbsp;than in the shallow (4.0ms&minus;1&nbsp;because they&#39;ve got more space to move!</li>
	</ul>
	</li>
</ul>

<ul>
	<li>Practice Question 1:
	<ul>
		<li>Glass slab in water, refractive index stuff, angles, and more calculations! Don&#39;t forget Snell&#39;s Law!</li>
	</ul>
	</li>
	<li>Practice Question 2:
	<ul>
		<li>Light goes from air to diamond and vice versa. More angles, refractive indices, and drawing. Ready for some diamond shine?</li>
	</ul>
	</li>
</ul>

Remember: Always look at things from different angles, just like light does!

Theme C - Wave Behaviour

Mastering Snell's Law: The Physics of Refraction Explained

Table of content

Snell's law

Light in a vacuum

Refractive index part 2

Refraction's physics

Unlock the Full Content!

Theme C - Wave Behaviour

Mastering Snell's Law: The Physics of Refraction Explained

Table of content

Snell's law

Light in a vacuum

Refractive index part 2

Refraction's physics

Unlock the Full Content!