Physics 3 - 13.3 Orbital Forces

What provides the centripetal force for planets and satellites?

• In 1687, Newton published "Principia", the central concept of which was that all particles in the universe attract all other particles
• The size of the force between two objects depends on their masses and how far apart they are

F  =  Gm1Gm2

              r2

Where 'r' is the distance between the centre of masses of each object and G is the universal gravitational constant (6.67x10-11Nm2Kg-2)

The bigger the mass of the bodies, the bigger the force of gravity between them. As the distance between two bodies increases, the force…