Part B: Gravitational Potential Energy 1. Mathematically we describe the gravitational potential energy (GPE) at a given position when GMm using the equation: Eg= under the graph in Part A Q#2. which is the result of the calculus work describing the area 2. Fill in the chart showing the gravitational potential energies for a 1 kg rock at different positions from the centre of the earth. (Re = 6.4 x 106 m. Me = 60 x 1024 kg) Sketch this as a graph. + Distance from centre of earth Eg 3. Use greater than or less than symbols to compare: Re 2Re 3Re 4Re 6Re 8Re Eg(Re) Eg(Re) Eg(2Re) Eg(really, really far) far 4. According to your graph, at what position is the greatest amount of energy stored in the gravitational field? Really, really Note! Really, really far means an infinitely large distance + 5. What is the change in GPE when the rock travels from: a) 2Re to 6Re b) 8Re to 4Re c) Re to infinity d) infinity to Re 6. Is energy being stored in or returned from the gravitational field when AEg is: a) positive? b) negative? 7. Imagine a small rocket engine is attached to the rock. How much work is done by the rocket engines to move the rock from: a) 2Re to 6Re, b) Re to infinity (+