1.1.4 Gravitational Potential Energy

• Gravitational potential energy is the energy an object has due to its height in a gravitational field.
• If an object is lifted up, energy is transferred to its gravitational potential store.
• If an object falls, energy will be transferred away from its gravitational potential store.
• The gravitational potential energy, Ep, of an object can be calculated using the equation: Ep = m × g × h.
• The gravitational field strength (g) on the Earth is approximately 9.8 N/kg.
• The gravitational field strength on the surface of the Moon is less than on the Earth.
• m = mass, in kilograms (kg).
• This means it would be easier to lift a mass on the Moon than on the Earth.
• The gravitational field strength on the surface of the gas giants (eg Jupiter and Saturn) is more than on the Earth.
• This means it would be harder to lift a mass on the gas giants than on the Earth.