# Physics (P4, P5 & P6)

Mindmap for OCR 21st Century New for 2011 Physics exam (P4, P5 & P6)

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• Created by: Zoe
• Created on: 03-01-13 12:40
• Physics
• P4
• Work Done
• The thing doing the work needs an energy supply e.g. Fuel or food
• Work Done (J) = Force (N) X Distance moved (m)
• Always measured in Joules (J)
• Energy Transfered
• Resultant Forces
• Decides the motion of the object
• If there is a resultant force, the speed or direction (or both) will change
• Overall force acting on an object
• P5
• Electric Current
• Electric Current is a flow of charge around a  circuit
• Current will only flow thorough a component if there's voltage across that component
• Conductors & Insulators
• A Conductor doesn't hold onto electrons, it alows them to flow/move easily
• An insulator holds onto electrons, they cannot flow easily
• Resistance
• The steeper the graph the lower the resistance
• P6
• The number of Neutrons in an atom isn't fixed
• Alpha = Ionising Helium Nucleus
• Beta = Electrons
• Gamma = Electromagnetic Wave
• Half-Life
• Time taken for the number of undecayed nuclei [activity] to decrease by half
• Nuclear Fusion
• Coverts mass into energy
• E = mc(squared)