Phys MCE

• Equilibrium


  All moments on an object are balanced
• Helical spring graph

  
• Metal Wire graph

  
• Rubber Band graph

  
• An object that obeys Hooke's Law when...

  ...the force and the extension are directly proportional to each other
• Principle of Moments


  anti-clockwise moment = clockwise moment when

  
• Stopping Distance


  The sum of thinking distance and the braking distance
• Thinking Distance


  the distance travelled by the vehicle in the time it takes the driver to react
• Braking Distance


  The distance your car travels after you apply the brakes
• Terminal Velocity


  the constant velocity of a falling object when the force of air resistance is equal in magnitude and opposite in direction to the force of gravity
• Displacement


  Distance traveled in a particular direction from a specific point
• Vector


  A quantity which has both size and direction
• Scalar


  A quantity which only takes size into account
• Center of gravity


  the point around which an object's weight is evenly distributed.
• Induced charges


  Charges that appear on an uncharged object because of a charged object nearby
• Dangers of electrostatic


  Clothes can become charged from charges which escape the earth, causing electric shocks. Aircrafts can become charged due to air resistance in the air, if discharged quickly an explosion from the spark may happen
• Uses of electrostatic


  The negative charge of an electrostatic paint can be applied evenly to a positively charge object
• Live wire


  Path for electrical energy

  
• Neutral wire


  Completes the circuit

  
• Earth wire


  To protect if there is a fault

  
• Fuse


  Hey, send metal wire in a glass casing which melted. The current is too strong.

  
• Double insulation


  Used for appliances without an earth wire

  Have plastic casings and designed so that the live wire cannot touch the casing
• Alternate current


  Current and voltage for mains increase in decrease Because of how energy is generated
• Direct current


  Sales and batteries provide current voltage that don't fluctuate
• Conventional current


  Imaginary flow of electrons from the positive to negative
• Flow of electrons


  The flow of electrons from a negative to positive terminal
• Ohm's law


  The current in a conductor is directly proportional to the potential difference across its end, provided the temperature remains constant

  
• Current in a series

  Same
• Voltage in series


  Shared
• Current in parallel


  Shared
• Voltage in parallel


  Same
• Amps and coulombs


  A current of one amp in a wire means one coulomb of charge passing through a wire each second
• Fixed resistors


  Limits the size of current

  
• Fix resistors graph


  V and I are proportional, so follows ohms law

  
• Lamps graph


  V and I aren't proportional so it does not follow ohms law

  
• Lamps graph explained


  The lamp heats up as more electricity passes through causing resistance to increase as particles vibrate more
• Diode


  One way flow

  
• Diode graph


  V and I are not proportional so does not follow ohms law

  
• LDR


  A resistance which changes when light is shown on it

  
• What happens to the LDR when it's bright

  Resistance goes down