part 1

• scalar quantities have size only
• scalar vectors have magnitude only
• vector quantities have size and direction
• a vector can be represented by an arrow
• the length of the arrow represents the magnitude of the vector quantity
• the direction of the arrow shows the direction of the vector quantity
• a force is a push or pull that acts on an object due to the interaction with another object
• what is a force

  a push or pull that acts on an object due to the interaction with an object
• contact forces include

  air resistance , tension , normal contact force
• a force is a vector quantity
• weight is the force acting on an object due to gravity
• what is weight

  the force acting on an object due to gravity
• the weight of an object depends on the gravitational field strength at the point where the object is
• what does the weight of an object depend on

  the gravitational field strength where the object is
• weight = mass x gravitational field strength
• the weight of an object acts at a single point called the center of mass
• where does the weight of an object act

  the center of mass
• an objects weight and mass are directly proportional
• weight is measured using a newton meter
• how do we measure weight

  with a newton meter
• what is a resultant force

  a single force that has the same effect as all the original forces acting together
• A single force can be resolved into two components acting at right angles to each other . the two component forces have the same effect as the single force
• when a force causes the displacement of an object itvhas done work
• a force does work when

  it causes displacement
• work done = force x distance moved
• 1 joule = one newton meter
• stretching is caused by pulling forces
• compression is caused by pushing forces
• bending forces can be push or pull
• the center of an object always bends the most
• applying a single force causes movement
• applying multiple forces causes change of shape
• force = spring constant x extension
• what is hookes law

  describes the relationship between force applies to elastic object and the extension of the elastic object
• what is the spring constant

  the springs stiff ness
• linear relationships obey hookes law
• resultant force = mass x acceleration
• resultant force = thrust - drag
• weight = mass x gravitational field strength