4.3 and 4.4

• When two opposite forces are not balanced, there is a net force.
• When one force on an object is bigger than the opposite force, the forces are unbalanced.
• When both forces on an object are the same size, the forces are balanced.
• What can forces do?

  Forces can make thing move.
• What is work?

  The amount of energy transferred to an object to make it move is called work.
• What is net force?

  When two opposite forces are not balanced, there is a net force.