describing motion

• what is a scalar quantity

  • a quantity with only magnitude and no direction
• what is a vector quantity

  • a quantity with both magnitude and direction
• examples of scalar quantites

  • distance,time,mass,speed
• examples of vector quantities

  momentum,velocity,displacement,weight
• what is the difference between distance and displacement

  distance is how long/far an object is between two neighbouring points

  displacement is a distance in a given direction
• what is the difference between speed and velocity

  • speed is the how far an object travels per second
  • velocity is speed in a given direction or change in distance in a given time
• what is the equation for speed

  speed = distance/ time

  (m/s) meters seconds

  average speed is total distance
• what is accleration

  change in velocity / time

  a = final velocity - initial / time
• what is uniform accleration

  • uniform accleration is the constant acceleration of an object
  • all objects in free fall are 10m/s
  • to work it out we need to write values we do have and maybe even use another equation such as speed = distance / time if we aren't given it
• distance time graphs

  • gradient = speed
  • steeper gradient = faster speed less steep = slower gradient
  • stationary objects are represented with a horizontally laugh
  • accleration = deceleration is represented by objects that change
• velcotiy time graphs

  • graident = accleration because velocity / time = accleration
  • area under represents distance
  • -- line = constant accleration
  • / = increase and other way round = decrease
• average speeds

  walking - 1.5

  running - 3

  cycling = 6

  in car = 20
• things that can effect average speed

  • age
  • length fitness
• why is average speed less than top speed

  • not the same throughout
  • slower to begin with but faster at the end