Orbital Motion Lab for A Level Physics

Launch a satellite too slowly, at circular-orbit speed, into an ellipse or at escape speed and watch the inverse-square gravitational field determine its path.

Learning guide and suggested activities

What this tool shows

  • Why a sideways launch can produce impact, a circle, an ellipse or escape
  • How velocity remains tangent while gravitational acceleration points inward
  • How launch speed compares with circular and escape speed
  • How negative or non-negative total energy distinguishes bound and unbound paths
  • Why satellite mass does not change the orbital trajectory

OCR A relevance

  • OCR A Module 5.2.2: Gravitational fields
  • Circular satellite orbits and Kepler’s third law
  • Gravitational potential and escape speed

AQA relevance

  • AQA 7408 sections 3.7.1 and 3.7.2
  • Gravitational field strength and potential graphs
  • Circular orbits, satellite energy and escape velocity
  • Synchronous, geostationary and low Earth orbits

Try these tasks

  • Compare a 400 km low Earth orbit with the geostationary preset.
  • Increase orbital radius and explain every change in g, V, v, T and total energy.
  • Change satellite mass and identify which quantities do not change.
  • Use the graph marker to connect the slope of V against r with field direction.