Momentum and Moment (pg 12-14) T.S

Cards (18)

  • Formula for momentum: Momentum=Momentum=MassMass *VelocityVelocity
  • Formula for momentum: p=p=mvmv
  • The greater the mass of an object and the greater its velocity, the more momentum the object has
  • Momentum is a vector quantity - it has size and direction
  • Momentum is conserved when no external forces act. Momentum before = momentum after
  • When a force acts on an object, it causes a change in momentum
  • Formula for force with change in momentum: F=F=(mvmu)/t(mv-mu)/t
  • Formula for change in momentum: force = change in momentum / time
  • A larger force means a faster change of momentum
  • Cars are designed to slow people down over a longer time when they crash - the longer is takes for a change in momentum, the smaller the force
  • A moment is the turning effect of a force
  • Formula for moment: Moment (Nm) = Force (N) * Perpendicular distance between line of action and pivot (m)
  • The centre of gravity hangs directly below the point of suspension
  • A freely suspended object will swing until its centre of gravity is vertically below the point of suspension
  • For simple shapes, you can find the centre of gravity by looking for lines of symmetry
  • The principle of moment says that if an object is balanced then:
    Total Anticlockwise Moments = Total Clockwise Moments
  • If a heavy object is placed on a rod, the support closest to the object will provide a larger force
  • If the anticlockwise moments do not equal the clockwise moments, there will be a resultant moment. (So the object will turn)