Work Done on a Mass

• What is done when a mass is moved against gravity?

  Work is done
• How is work done in moving a mass expressed mathematically?

  ∆W = m∆V
• What does ∆W represent in the equation ∆W = m∆V?

  Change in work done (J)
• What does m represent in the equation ∆W = m∆V?

  Mass (kg)
• What does ∆V represent in the equation ∆W = m∆V?

  Change in gravitational potential (J kg)

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

  They are equal
• When is gravitational potential energy (G.P.E) equal to zero?

  When V = 0
• How is the change in G.P.E expressed for a mass m at distances r and r'?

  ΔG.P.E = m(g(r') - g(r))

  
• What does M represent in the context of gravitational fields?

  Mass producing the gravitational field
• What does m represent in the context of gravitational fields?

  Mass moving in the gravitational field
• What does r represent in the context of gravitational fields?

  Distance from the center of mass
• What happens when an object moves against gravitational field lines?

  Work is done
• How does gravitational potential energy change as a satellite leaves the Moon's surface?

  It increases

  
• What are equipotential lines and surfaces?

  They join points with the same gravitational potential

  
• How are equipotential lines oriented in relation to gravitational field lines?

  Perpendicular to gravitational field lines

  
• How are equipotential lines represented visually?

  By dotted lines
• What happens to equipotential lines in a radial field as distance increases?

  They can become further apart
• Why do equipotential lines become further apart in a radial field?

  Potential decreases with distance
• What is the characteristic of equipotential lines in a uniform field?

  They are horizontal straight lines

  
• What is the spacing of equipotential lines in a uniform field?

  Equally spaced

  
• What happens when moving along an equipotential line?

  No work is done
• What is the change in potential when moving along an equipotential line?

  ΔV = 0
• How are gravitational equipotential lines in a uniform gravitational field characterized?

  They are equally spaced

  
• What should not be included on equipotential lines?

  No arrows
• How should equipotential lines be drawn?

  With a ruler or straight edge