Forces

• Magnitude


  The size of a physical quantity
• Physical quantity


  Something that can be measured and expressed in numerical values
• Scalar


  A physical quantity that has magnitude (size) only.
• Vector


  A physical quantity that has both magnitude (size) and direction
• Contact forces


  Force exerted between two objects when they are touching
• Force


  A push or a pull. The unit of force is N (Newtons)
• Non-contact forces


  The push or pull acting between objects that are not physically touching
• Attraction


  When two or more things come together
• Repulsion


  When two or more things are forced apart
• Gravitational field strength


  Force per unit mass. Measured in N/kg
• Weight


  The force acting on an object due to the pull of gravity on a massive object. The force acts towards the centre of the object. Measured in Newtons
• Mass


  The amount of matter an object contains. mass is measured in kg or g
• Work done


  The amount of energy it takes to do a task. Measured in Joules (J)
• Elastic


  Elastic materials return to their original shape and size after being stretched or squashed
• Inelastic


  inelastic materials do not return to their original shape and size after being stretched or squashed
• Work done


  Energy transferred by a force
• Elastic potential energy


  Energy stored in squashed, stretched or twisted materials
• Moment


  A turning effect of a force
• Equilibrium 


  In physics, an object in equilibrium will not turn or accelerate- there is no overall force
• Pressure 


  Force exerted over an area
• Internal energy 


  The total kinetic energy and potential energy of the particles in an object
• Altitude 


  A measure of an areas height above sea level
• Velocity 


  The speed of an object in a particular direction
• Displacement


  Quantity describing the distance from the start to the end of a journey
• Air resistance 


  a force of friction produced when an object moves through the air
• Resultant force 


  The single force that could replace all the forces acting on an object. if all the forces are balanced the resultant force is 0
• Terminal velocity


  The maximum speed of an object reached when the forces moving the object are balanced
• Inertia 


  The tendency of an object to continue in its current state unless acted on by a resultant force
• Momentum


  A quantity relating to a moving object
• Vector 


  Describes a movement from one point to another