Gravitation

Gravitation

1. Newton's law/; universal attractive force acting between all matter

   • F=GMm/r^2

2. Gravitational Field Strength

   • force field= a region in which a body experiences a force
     • represented by gravitational field lines
   • g force per unit mass= F/M
   • g in a radial field= GM/r^2

3. Gravitational Potential

   • work done per unit mass to move the object from infinity to the point
   • at infinity gravitational potential is zero
   • work done= m*change in V
   • GPE in a radial field=GM/r

4. g and V represented graphically

5. Satellite motion

   • an object in a circular orbit is in circular motion, the centripetal force is the gravitational force so the equations can be combined
   • geostationary satellites have an orbital period of 24hrs so they stay in the same space in the sky

Images and files in the map