Gravitational Potential

• What is the formula for gravitational potential energy (G.P.E)?

  G.P.E = mgΔh
• What is the gravitational potential energy on the surface of the Earth?

  It is taken to be zero
• What does lifting an object do in terms of energy?

  Work is done to lift the object
• For which objects is the G.P.E equation applicable?

  Objects within the Earth's surface
• How is G.P.E defined outside the Earth's surface?

  Energy due to position in a gravitational field
• What is the gravitational potential at a point?

  G.P.E per unit mass at that point
• How is gravitational potential defined mathematically?

  Work done per unit mass from infinity
• What symbol represents gravitational potential?

  V
• In what units is gravitational potential measured?

  J kg^-1
• Why is gravitational potential always negative?

  Defined as zero at infinity
• What does the negative gravitational potential indicate?

  Work must be done to reach infinity
• How does gravitational potential change with distance from a mass?

  It increases (becomes less negative)
• What happens to gravitational potential as a satellite moves closer to Earth?

  It decreases

  
• What is the relationship between gravitational potential and gravitational potential energy?

  • Different gravitational potentials exist at different distances from a mass
  • Gravitational potential difference (ΔV) is defined as:
  • ΔV = V_f - V_i
  • A difference in gravitational potential leads to a difference in gravitational potential energy
• What does ΔV represent?

  Gravitational potential difference
• What is the equation for gravitational potential difference?

  ΔV = V_f - V_i
• What should you remember when calculating differences in values denoted by Δ?

  Calculate as final value minus initial value
• What does a negative difference in gravitational potential indicate?

  The value is decreasing