forces ep 2

• Non-contact forces


  Forces where objects do not touch or are not in contact with each other
• Examples of non-contact forces

  • Gravitational force
  • Magnetic force
• Gravitational force


  The force that attracts objects towards the earth
• Gravitational force is the main reason why we get to enjoy walking, running and living on earth</b>
• Without gravitational force, everything will float and many things would be very challenging to do
• Normal force


  The force that acts perpendicular to the surface which an object is in contact with
• If there is an upward normal force and an object at rest

  There is also a downward gravitational force that pulls it downwards
• Gravitational force


  The weight of an object that pulls it downward, greater mass means greater gravitational force
• Magnetic force


  The force that is exerted in a field of attraction or repulsion between magnets and magnetic materials
• Magnets don't necessarily need to be in contact with other magnetic materials to make them move
• Balanced forces


  Forces that are of opposite directions and equal in magnitude, resulting in no change in motion
• Unbalanced forces


  Forces that are in opposite direction and unequal in magnitude, resulting in a change in motion
• Net force/Resultant force


  The sum of all the forces that act on an object
• Solving net force


  Use the formula: net force = sum of all forces

  Use positive and negative signs to indicate direction
• If the net force is zero, the forces are balanced and there is no change in motion
• If the net force is not zero, the forces are unbalanced and there will be a change in motion