physics nat 5

• As gas is heated

  pressure rises
• 1 pascal =


  1 newton per square metre
• the bigger the area

  the smaller the pressure
• the higher the temperature


  the more particles move
• heat is a measure of the total kinetic energy of the particles in an object
• temperature is a measure of the average kinetic energy of the particles in an object
• newtons first law

  an object will remain at rest or continue moving at a constant speed in a straight line unless an unbalanced force acts upon it
• newtons second law


  when the forces acting on an object are unbalanced, the object will accelerate in the direction of the unbalanced force
• newtons third law


  for every action there is an opposite and equal reaction
• switch

  
• What are the units for work done

  Joules J
• what are the units for activity

  Becquerels Bq
• what are the units for electric charge

  Couloms C
• what are the units for electric current

  Amperes A
• what are the units for power

  watts W
• In a series circuit what happens with the voltage

  the voltage must add up between the components to the voltmeter measure
• whats the order of the electromagnetic waves


  Radiowaves, microwaves, infrared, visible light, ultraviolet, xrays, gamma rays
• the waves with the greatest energy have the greatest


  frequency
• as the frequency of waves increases the wavelength


  decreases
• 1 becquerel =


  1 decay per second
• what are the units for absorbed does (D)

  Grays Gy
• what are the units for equivelent does rate (H)

  sieverts Sv
• what is a vector

  a quantity that has magnitude and direction
• what is a scaler

  a quantity that has magnitude only
• to increase friction we can:

  increase the size of the surface areas to rub or us materials with rougher surface area
• to decrease friction we can:


  streamline shape or use lubricant
• resistance is the 


  opposition to current flow
• in a series circuit the

  current is the same at every point
• in a series circuit the

  voltage splits up across the component
• in a parallel circuit the

  voltage across each branch is equal to the supply voltage
• in a parallel circuit the

  current splits up through each branch
• resistors in parallel = 1/Rt = 1/R1 + 1/Rt + ...
• resistors in series = Rt = R1 +R2 + ...
• Why does a LED always have a resistor in series with it

  The resistor protects the LED from too high a current
• what is a LDR

  An LDR is a light dependent resistor and therefore its resistance varies according to the light incident upon it (LURD)
• what is a thermistor

  A thermistor is a temperature dependent resistor and therefore its resistance varies according to its temperature
• As temperaturre decreases

  pressure decreases
• from more dense to less dense material light bends away from the normal
• direct current


  is when the current flows in only one direction all the time
• alternating current

  is when the current will flow ne way for a period of time before stopping and flowing in the other direction