forces and their effects

• contact force - objects physically touch each other
• contact forces

  • friction
  • air resistance
  • tension
• non contact force - physically not touching eachother
• non contact forces

  • electrostatic
  • magnetic
  • gravitational
• opposite magnetic poles - attract
• like magnetic poles - repel each other
• moment - turning effect of a force
• moment of a force = force x distance
• if in equillibrium

  • anticlockwise moment = clockwise moment
• lever - force multiplier
• gears

  • wheels with toothed edges
  • as one gear rotates the other gear rotates in the opposite direction