Difference between revisions of "Gravitational Potential Energy Store"
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g on Earth is 9.8N/kg | g on Earth is 9.8N/kg | ||
− | | style="height:20px; width:200px; text-align:center;" |A pulley is used to lift a 12 tonne [[mass]] 0.80m above the ground. Calculate the change in energy in the gravitational potential store. | + | | style="height:20px; width:200px; text-align:center;" |A pulley is used to lift a 12 tonne [[mass]] 0.80m above the ground. Calculate the change in energy in the '''gravitational potential store'''. |
g on Earth is 9.8N/kg | g on Earth is 9.8N/kg |
Revision as of 18:25, 31 January 2019
Contents
Key Stage 3
Meaning
The gravitational potential energy store is the energy stored in an object that is in a gravitional field.
About The Gravitational Potential Energy Store
- The stronger the gravitational field the more energy in the gravitational potential energy store.
- The greater the mass of the object the more energy in the gravitational potential energy store.
- The greater the height of the object the more energy in the gravitational potential energy store.
Equation
The equation for gravitational potential energy written in words. |
The equation for gravitational potential energy written in symbols. |
Key Stage 4
Meaning
The gravitational potential energy store is the energy stored in an object that is in a gravitional field.
About Gravitational Potential Energy
- Gravitational Potential Energy is a potential energy due to the position of a mass in a gravitational field.
- The gravitational potential energy store of an object is related to three important factors:
- The mass - The greater the mass of an object the greater the gravitational potential energy.
- The gravitational field strength - The greater the gravitational field strength the greater the gravitational potential energy.
- The height of the object - The greater the height of an object in a gravitational field the greater the gravitational potential energy.
Equation
NB: You must memorise this equation!
Gravitational Potential Energy = (Mass) x (gravitational field strength) x (change in height)
\(E_g = m g \Delta h\)
Where:
Eg = Gravitational Potential Energy stored.
g = The gravitational field strength.
Δh = The change in height of the object.
Calculating Gravitational Potential Energy
A weight lifter lifts a 50kg mass a distance of 2.0m from the ground. Calculate the increase in gravitational potential energy of the mass.
g on Earth is 9.8N/kg |
A pulley is used to lift a 12 tonne mass 0.80m above the ground. Calculate the change in energy in the gravitational potential store.
g on Earth is 9.8N/kg Give your answer correct to two significant figures. |
During a rock slide a 320kg boulder falls from a height of 1450m to a height of 730m above sea level. Calculate the change in gravitational potential energy.
g on Earth is 9.8N/kg Give your answer correct to two significant figures. |
1. State the known quantities
m = 50kg g = 9.8N/kg Δh = 2.0m |
1. State the known quantities
m = 12tonne = 12,000kg g = 9.8N/kg Δh = 0.80m |
1. State the known quantities
m = 320kg g = 9.8 N/kg Δh = h2 - h1 = 1450 - 730 = 720m |
2. Substitute the numbers into the equation and solve.
\(E_g = m g \Delta h\) \(E_g = m \times g \times \Delta h\) \(E_g = 50 \times 9.8 \times 2\) \(E_g = 980J\) |
2. Substitute the numbers into the equation and solve.
\(E_g = m g \Delta h\) \(E_g = m \times g \times \Delta h\) \(E_g = 0.80 \times 9.8 \times 12000\) \(E_g = 94080J\) \(E_g \approx 94000J\) |
2. Substitute the numbers into the equation and solve.
\(E_g = m g \Delta h\) \(E_g = m \times g \times \Delta h\) \(E_g = 320 \times 9.8 \times 720\) \(E_g = 2257920J\) \(E_g \approx 2300000J\) |