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Physics Keywords
Keywords for junior cert physics
| Term | Definition |
|---|---|
| Speed | Distance travelled by an object in a unit of time |
| Velocity | Speed of an object in a given direction |
| Acceloration | Change in Speed/Time taken |
| Force | Causes a stationary object to move |
| Friction | A force that opposes the sliding motion of an object when in contact with another object |
| Lubrication | Used to reduce friction between two substances in contact |
| Weight | The pull of the earth on an object |
| Hooke's law | The extension of an elastic body is directly proportional to the force causing the extension |
| Lever | A rigid body that can turn about a fixed point called the fulcrum |
| Law of the lever | When a lever is balanced the sum of its clockwise moments = the sum of its anti-clockwise moments |
| Centre of gravity | A point in an object where all its weight appears to act |
| Pressure | Amount of force acting on a unit of area |
| Work | Force x Distance |
| Energy | The ability to do work |
| Power | Rate at which work is done |
| Latent Heat | Change in state but not a change in temperature |
| Dispersion | The spreading of light into its different colours |
| Reflection | The bouncing of light off a surface |
| Refraction | The bending of light as it passes through another medium |
| Sound | A form of energy produced when particles in an object vibrate |
| Magnetic Force | Force of attraction or repulsion between 2 magnets |
| Magnetic Field | The region around a magnet in which the magnetic force can be detected |
| Insulator | A material through which charge cannot flow |
| Conductor | A material through which charge can flow |
| Alternating Current | A current that flows in a continually changing direction |
| Direct current | A current that flows in one direction only |
| Diode | Allows current to flow |
| LED | Light Emitting Diode |
| LDR | Light Dependent Resitor |
| Ohm's Law | Voltage is directly proportionate to current |
| Echo | Reflection of sound |