MOMENTS

Moments – Remember it!

Moments – Remember it!

  • Physics GCSE science revision- momentsThe moment is the turning effect of the force and can be increased by increasing the length of the instrument being used or the amount of force being used.
  • moment = force x perpendicular distance from pivot
  • The force exerted is known as the effort, the object is called the load, and the pivot the turning point.
  • The centre of mass or the centre of gravity is an imaginary point within an object where we say the weight is acting.
  • An object is in equilibrium when the centre of mass lies directly under the point of suspension.
  • The turning effect causes an object in non-equilibrium to move back into equilibrium.
  • The pivot doesn’t have to be in the centre of an object for a moment to be in balance.
  • sum of all clockwise moments about a point = sum of all anti-clockwise moments
  • W1 x D1 = W2 x D2
  • All objects have a certain stability.
  • When the weight’s line of action is outside the base of the object it topples over.
  • Physics GCSE science revision- momentsWhen an object is moving in a circular direction at a constant speed at any moment its velocity is continuously changing direction as it moves around in the circle and the velocity is directed to the circle of direction along a tangent.
  • The force being placed on the object acts towards the centre of the circle as is called the centripetal force.
  • All object exert a gravitational force on each other.
  • Gravity is a force of attraction, increases as the mass of the objects increases and decreases as the distance between the objects increases.
  • Objects orbit objects larger than themselves.
  • There’s a centripetal force present due to the gravitational forces of attraction between the larger object and the smaller ones.
  • The planets further from the Sun travel at a slower speed because the gravitational force is weaker.
  • Like planets, the further away a satellite is to Earth, the slower it travels.
  • Satellites need to be travelling at the right speed in order to start orbiting the Earth.