Gravitation

• Gravitational field strength 


  The gravitational field strength of a point is defined as the gravitational force acting on a unit mass
• Gravitational potential 


  Gravitational potential at a point in a gravitational field is the work done by external forces moving a unit mass from infinity to that point.
• Change in gravitational potential


  V change = V final - V initial
• What is conservation field 


  The energy required to move a mass between two points in a gravitational field is independent of the path taken
• Given an example of a non conservation field

  Work done against friction.
• What is escape velocity

  The escape velocity from a plant is defined as the minimum velocity required to just escape from the planets gravitational field and reach infinity with zero velocity.
• Total energy on planets surface = total energy pf infinity =0


  Ek + Ep = 0 Derive