Difference between revisions of "Elastic Potential Energy Store"
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==Key Stage 4== | ==Key Stage 4== | ||
| + | {{#ev:youtube|https://www.youtube.com/watch?v=Pe4lX_FcqZ4}} | ||
===Meaning=== | ===Meaning=== | ||
The '''elastic potential energy store''' is an [[Energy Store|energy store]] associated with stretched, squashed and twisted elastic [[object]]s. | The '''elastic potential energy store''' is an [[Energy Store|energy store]] associated with stretched, squashed and twisted elastic [[object]]s. | ||
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: The '''elastic potential energy store''' of an [[object]] is related to two [[property|properties]] of the [[object]]: | : The '''elastic potential energy store''' of an [[object]] is related to two [[property|properties]] of the [[object]]: | ||
*The [[Spring Constant]] of the [[object]]. - The amount of [[force]] needed to stretch or squash it's shape by a given distance. The greater the [[Spring Constant|spring constant]] the greater the '''elastic potential energy''' stored. | *The [[Spring Constant]] of the [[object]]. - The amount of [[force]] needed to stretch or squash it's shape by a given distance. The greater the [[Spring Constant|spring constant]] the greater the '''elastic potential energy''' stored. | ||
| − | *The [[ | + | *The [[extension]] of the [[object]]. - The distance that the [[object]] has been stretched or squashed. The greater the [[extension]] the greater the '''elastic potential energy''' stored. |
===Equation=== | ===Equation=== | ||
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k = The [[Spring Constant|spring constant]] of the [[object]]. | k = The [[Spring Constant|spring constant]] of the [[object]]. | ||
| − | x = The [[ | + | x = The [[extension]] of the [[object]]. |
===Calculating Elastic Potential Energy=== | ===Calculating Elastic Potential Energy=== | ||
| + | {{#ev:youtube|https://www.youtube.com/watch?v=v7uBIR9RWe0}} | ||
{| class="wikitable" | {| class="wikitable" | ||
| style="height:20px; width:200px; text-align:center;" |A bow with a spring constant of 400N/m is stretched 0.5m with a force of 200N. Calculate the elastic potential store of the bow. | | style="height:20px; width:200px; text-align:center;" |A bow with a spring constant of 400N/m is stretched 0.5m with a force of 200N. Calculate the elastic potential store of the bow. | ||
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Final Length = 9.1m | Final Length = 9.1m | ||
| − | '''Find the [[ | + | '''Find the [[extension]].''' |
x = Final Length - Original Length = 9.1 - 0.1 = 9.0m | x = Final Length - Original Length = 9.1 - 0.1 = 9.0m | ||
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<math>E_e \approx 32J</math> | <math>E_e \approx 32J</math> | ||
|} | |} | ||
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| + | ===References=== | ||
| + | ====AQA==== | ||
| + | |||
| + | :[https://www.amazon.co.uk/gp/product/178294558X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294558X&linkCode=as2&tag=nrjc-21&linkId=f0dfb66dafcb0c6e9449e7b1a4ae1ac110 ''Elastic potential energy stores, pages 12, 55, 56, GCSE Physics; The Revision Guide, CGP, AQA ''] | ||
| + | :[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09874 ''Elastic potential energy stores, pages 169, 206, 207, GCSE Combined Science; The Revision Guide, CGP, AQA ''] | ||
| + | :[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Elastic potential energy stores, pages 21, 27, 28, 141, GCSE Combined Science Trilogy; Physics, CGP, AQA ''] | ||
| + | :[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Elastic potential energy stores, pages 22, 28, 29, 161, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA ''] | ||
| + | |||
| + | ====Edexcel==== | ||
| + | |||
| + | :[https://www.amazon.co.uk/gp/product/1782948163/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948163&linkCode=as2&tag=nrjc-21&linkId=0fdbfd5dd397d6e24a9dfb250f08587f ''Elastic potential energy stores, pages 61, 325, GCSE Physics, CGP, Edexcel ''] | ||
| + | :[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Elastic potential energy, page 316, GCSE Combined Science, Pearson Edexcel ''] | ||
| + | :[https://www.amazon.co.uk/gp/product/1292120223/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120223&linkCode=as2&tag=nrjc-21&linkId=068ecf40278c32406a7f1c6e66751417 ''Elastic potential energy, page 34, GCSE Physics, Pearson Edexcel ''] | ||
| + | |||
| + | ====OCR==== | ||
| + | :[https://www.amazon.co.uk/gp/product/1782945695/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945695&linkCode=as2&tag=nrjc-21&linkId=ceafcc80bcad6b6754ee97a0c7ceea53 ''Elastic potential energy stores, pages 171, 202, 206, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR ''] | ||
| + | :[https://www.amazon.co.uk/gp/product/1782945687/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945687&linkCode=as2&tag=nrjc-21&linkId=9a598e52189317a20311d7a632747bc9 ''Elastic potential energy stores, pages 37, 82, 86, Gateway GCSE Physics; The Revision Guide, CGP, OCR ''] | ||
Latest revision as of 01:44, 5 December 2019
Contents
Key Stage 3
Meaning
The elastic potential energy store is an energy store associated with stretched, squashed and twisted elastic objects.
About Elastic Potential Energy
Examples
 |
 |
 |
| Rubber bands can store elastic potential energy when they are stretched. | A spring stores energy in the elastic potential store when they are stretched, squashed and bent. | A stretched bow stores elastic potential energy. The further it is stretched the more energy it stores. |
Key Stage 4
Meaning
The elastic potential energy store is an energy store associated with stretched, squashed and twisted elastic objects.
About Elastic Potential Energy
- Any object that returns to its original shape after a deforming force has been removed is able to store elastic potential energy.
- Elastic potential energy is a Potential Energy store.
- The elastic potential energy store of an object is related to two properties of the object:
- The Spring Constant of the object. - The amount of force needed to stretch or squash it's shape by a given distance. The greater the spring constant the greater the elastic potential energy stored.
- The extension of the object. - The distance that the object has been stretched or squashed. The greater the extension the greater the elastic potential energy stored.
Equation
NB: You will be given this equation in the formula sheet.
Elastic Potential Energy = 0.5 x (Spring Constant) x (Extension)2
\(E_e = \frac{1}{2} k x^2\)
Where:
Ee = Elastic Potential Energy stored.
k = The spring constant of the object.
x = The extension of the object.
Calculating Elastic Potential Energy
| A bow with a spring constant of 400N/m is stretched 0.5m with a force of 200N. Calculate the elastic potential store of the bow. | A bungee cord with a spring constant of 45N/m stretches by 30m. Calculate the elastic potential store of the cord.
Give your answer correct to 2 significant figures. |
A slinky spring of length 0.1m and spring constant 0.80N/m is stretched to a length of 9.1m. Calculate the elastic potential store of the slinky.
Give your answer correct to 2 significant figures. |
| 1. State the known quantities
k = 400N/m x = 0.5m |
1. State the known quantities
k = 45N/m x = 30m |
1. State the known quantities
k = 0.8N/m Original Length = 0.1m Final Length = 9.1m Find the extension. x = Final Length - Original Length = 9.1 - 0.1 = 9.0m |
| 2. Substitute the numbers into the equation and solve.
\(E_e = \frac{1}{2} k x^2\) \(E_e = \frac{1}{2} \times 400 \times 0.5^2\) \(E_e = \frac{1}{2} \times 400 \times 0.25\) \(E_e = 50J\) |
2. Substitute the numbers into the equation and solve.
\(E_e = \frac{1}{2} k x^2\) \(E_e = \frac{1}{2} \times 45 \times 30^2\) \(E_e = \frac{1}{2} \times 45 \times 900\) \(E_e = 20250J\) \(E_e \approx 20,000J\) |
2. Substitute the numbers into the equation and solve.
\(E_e = \frac{1}{2} k x^2\) \(E_e = \frac{1}{2} \times 0.80 \times 9.0^2\) \(E_e = \frac{1}{2} \times 0.80 \times 81\) \(E_e = 32.4J\) \(E_e \approx 32J\) |
References
AQA
- Elastic potential energy stores, pages 12, 55, 56, GCSE Physics; The Revision Guide, CGP, AQA
- Elastic potential energy stores, pages 169, 206, 207, GCSE Combined Science; The Revision Guide, CGP, AQA
- Elastic potential energy stores, pages 21, 27, 28, 141, GCSE Combined Science Trilogy; Physics, CGP, AQA
- Elastic potential energy stores, pages 22, 28, 29, 161, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA
Edexcel
- Elastic potential energy stores, pages 61, 325, GCSE Physics, CGP, Edexcel
- Elastic potential energy, page 316, GCSE Combined Science, Pearson Edexcel
- Elastic potential energy, page 34, GCSE Physics, Pearson Edexcel