Energy Types and Transfers
Ever wondered why a bouncing ball eventually stops or how your phone battery powers the screen? It all comes down to energy types and how they transform from one form to another.
There are eight main types of energy you need to know. Kinetic energy involves movement (like a rolling football), whilst elastic energy is stored when things stretch (think rubber bands). Gravitational energy depends on height above ground - that's why dropping something from higher up creates more impact.
Chemical energy is stored in fuels and foods, which is why petrol powers cars and breakfast gives you energy for the day. Meanwhile, electrostatic and magnetic energy involve attraction and repulsion between charges and magnets respectively.
Here's the golden rule: energy cannot be created or destroyed - it only transfers between different types. Energy transfers happen in four main ways: mechanically (forces moving objects), electrically (charges flowing), through heating (temperature differences), and via radiation (like light waves).
Key Formula: For heating calculations, use ΔE = mcΔθ, where specific heat capacity tells you how much energy 1kg of a substance needs to increase by 1°C.
The specific heat capacity formula is essential for calculations involving temperature changes. You'll definitely see this in your exams, so make sure you can rearrange it to find any missing variable.