Physics

• scalar quantities are simply numerical value or size for example; speed
• vector quantities have both value, size and direction; for example velocity
• • speed unit (m/s)
  • distance unit (m)
  • time unit (s)
• • Speed = distance divided by time
  • distance = speed multiplied by time
  • time = speed multiplied by distance
• stationary means the object is not moving
• the gradient = speed

  the higher the slope is the faster the speed

  
• acceleration tells us how much our velocity changes per second
• acceleration = final velocity - initial velocity / time taken to travel the distance
• a= v-u/s
• velocity is the speed and direction of motion of an object
• Gradient = acceleration

  a flat line indications a constant speed, so if the line is flat on the graph that means the object did not more at all!

  
• velocity = Displacement divided by time
• displacement is another word for distance
• the area under need the velocity curve is the Total displacement
• a force is a push or a pull movement
• Newtons 3rd law;

  For every action there is an equal and opposite reaction.
• force is measures in newtons
• forces can:

  • change the speed
  • change their shape
  • change their direction
  • create friction
  • compress
  • drag
  • stretch or tension
  • twist or torsion
• resistance is a force that cannot be seen but you can see how a force affect an object

  eg:

  push - compression (squash)

  pull - tension (stretch)
• they are two types for forces

  contact:

  • a force that requires touch
  • contact force is a push or pull on one object by another object that is touching it.
  • examples of contact forces are: Friction, push and pull

  Non-contact:

  • forces that do not require touch
  • Non-contact forces act on an object without the need for physical contact
  • examples of non-contact forces are: magnetism, gravity and electrostatics
• gravitational forces:

  • exists between objects that have mass
  • on earth we experience gravity as a downward force
• magnetism forces:

  • can be attractive or repulsive
  • opposites attract; for example N, North Pole, and S, south pole, attract where as N and N repel.
  • is a non-contact force between two materials
• electrostatic forces:

  • occurs between charges
  • could be attractive or repulsive charges
  • electrostatic forces are found almost everywhere
  • They are created by the negative electrons on the outer shell of atoms
• Newtons first law of motion;

  every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.

  • at rest > stationary
  • Uniform motion > constant speed
  • compelled > made
• • Mass is how much matter an object is made up of, and is measured in kilograms
  • Mass example; if a cat has the mass of 12kg the cat will have 12kg everywhere around the universe
  • weight is the force of gravity, how strongly gravity pulls an object towards the earth and is measured in Newtons
  • weight example; the cats weight depends on the planet it is on and how strong the gravity is . You can calculate it with an equation. Weight = mass * GFS(g)
  • weight = MG
  • GFS = gravitational field strength