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Magnifying Glass Tilted Right

Theme D - Fields

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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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Water Wave

Theme C - Wave Behaviour 

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Microscope

Theme E - Nuclear & Quantum Physics

Gravitational potential energy is all about how high you lift something against the pull of gravity. If you&#39;ve ever lifted a heavy bag of groceries, congratulations! You&#39;ve given it some gravitational potential energy.

<ul>
	<li>When you move a mass m by a height &Delta;h in a gravitational field of strength g -&nbsp;&Delta;Eg​ = m &times; g &times; &Delta;h</li>
</ul>

👀 Keep in Mind

<ul>
	<li>Near Earth, g = 9.8N/kg. But it&#39;s smaller when you move away from Earth.</li>
	<li>This equation works best when g remains nearly constant over the height change.</li>
</ul>

<ul>
	<li>Earth&#39;s gravitational field looks pretty much the same to us humans, even though it&#39;s radial (spreads out in every direction).</li>
	<li>The field lines near the surface are nearly parallel and spaced out equally. So, it feels uniform.</li>
</ul>

The mg&Delta;h equation isn&#39;t always accurate

<ul>
	<li>Gravitational field strength changes with distance between masses.</li>
	<li>The equation kind of &quot;cheats&quot; by including Earth&#39;s mass in g.</li>
</ul>

<ul>
	<li>It&#39;s about the energy transferred (or the work done) to create a system from a starting point where the two masses don&#39;t feel each other&#39;s gravity.</li>
	<li>Imaginary Place Alert: &quot;Infinity&quot; - This is where our two masses start, and there&#39;s no gravitational attraction between them.</li>
	<li>Real-World Connection: Think of two magnets at a distance where they don&#39;t attract each other.</li>
</ul>

<ul>
	<li>
	Gravitational force between two masses changes as they move closer or further apart.
	</li>
	<li>
	For two objects of masses M and m at distance r, gravitational potential energy is: Ep = &ndash; \(\frac {Gm1m2}{r}\)

	(Don&#39;t worry about the negative sign, it just means that to separate the two objects, we need to add energy.)
	</li>
</ul>

<ul>
	<li>To pull two objects with mass apart: Add energy! 💡</li>
	<li>To let two objects with mass come together:&nbsp;Remove energy! 💤</li>
</ul>

Let&#39;s think of a satellite as a space delivery. We&#39;re sending it up above Earth!

&nbsp;

🛰️ Satellite Launch

<ul>
	<li>Satellite mass: 740kg</li>
	<li>Height above Earth: 320km</li>
	<li>Earth details: Radius =6.37&times;106m and Mass =5.97 &times; 1024kg</li>
</ul>

🎯 Tasks

<ul>
	<li>Find gravitational potential energy at Earth&#39;s surface.</li>
	<li>Find energy change when it&#39;s in orbit.</li>
</ul>

✨ Answers

<ul>
	<li>Energy at surface:&nbsp;Ep = &minus;4.63 &times; 1010J</li>
	<li>Energy change to orbit:&nbsp; &Delta; Ep = 2.21 &times; 109J</li>
</ul>

🧠 Think about it

<ul>
	<li>You need a lot of energy to send stuff to space. This is why rockets are massive but satellites comparatively tiny!</li>
</ul>

<ul>
	<li>Gravitational potential energy depends on height and gravity&#39;s strength.</li>
	<li>Near Earth, gravity feels constant but changes at larger distances.</li>
	<li>Two objects have gravitational potential energy based on their masses and distance apart.</li>
	<li>Always need energy to pull them apart!</li>
</ul>

🎉 Happy Learning! 🚀

Theme D - Fields

Gravitational Potential Energy: Understanding Its Intricacies Near Earth

Table of content

Introduction 🌌

Gravitational potential energy near earth 🍎

Why is g considered constant near earth?

On a larger scale 🌌

Unlock the Full Content!

Theme D - Fields

Gravitational Potential Energy: Understanding Its Intricacies Near Earth

Table of content

Introduction 🌌

Gravitational potential energy near earth 🍎

Why is g considered constant near earth?

On a larger scale 🌌

Unlock the Full Content!