Topic 9: forces and their effects

• What are the three main non contact forces

  Gravitational - 2 masses - always attractive

  Electromagnetic - 2 charges - like repel unlike attract

  Magnetic - 2 magnets - like repel unlike attract
• what is a normal force

  a force that acts in the opposite direction to weight
• give the 5 main vector quantities

  • force
  • velocity
  • acceleration
  • displacement
  • momentum
• give the five main scalar quantities

  • speed
  • distance
  • mass
  • energy
  • temperature
• how to draw a vector diagram

  1. find scale
  2. draw force
  3. draw horizontal and vertical components
  4. measure lengths
• what are the rules for resultant forces

  • vector quantity
  • same direction add
  • different direction subtract
• what is the rule about balanced and unbalanced forces

  unbalanced = acceleration

  balanced = constant velocity