Yr10 - energy and work
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Transcript of Yr10 - energy and work
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Dr Pusey
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Energy makes things happen
An object is said to have energy if it can cause some change to occur
“Energy is the ability to do work”
Energy is conserved – it cannot be created or destroyed
Energy is measured in Joules (J)
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Energy comes in different forms including:
gravitational potential
electrical potential
elastic potential
chemical potential
kinetic
heat
sound
light
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Mechanical energy is the energy types specifically related to motion
In this topic we are interested in:
gravitational potential energy (sometimes just called potential energy, PE or EP)
kinetic energy (KE, EK)
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Potential energy = stored energy
A result of an object’s position
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Potential energy = stored energy
A result of an object’s position
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Example 1
What potential energy does a 1 tonne wrecked car gain when a crane lifts it off the ground and puts it on top of a 3 m high pile of scrap?
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Example 1
What potential energy does a 1 tonne wrecked car gain when a crane lifts it off the ground and puts it on top of a 3 m high pile of scrap?
![Page 9: Yr10 - energy and work](https://reader030.fdocuments.us/reader030/viewer/2022033102/55d09fc9bb61ebd5688b45e0/html5/thumbnails/9.jpg)
Kinetic energy = moving energy
If an object is moving it has kinetic energy
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Kinetic energy = moving energy
If an object is moving it has kinetic energy
Kinetic Energy (J)
Velocity (m/s)
Mass (kg)
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Example 2
What is the kinetic energy of a 42 kg skateboard rider who has a velocity of 3.7 m/s East?
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Example 2
What is the kinetic energy of a 42 kg skateboard rider who has a velocity of 3.7 m/s East?
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The meaning of the word ‘work’ in physics is different from everyday use
Work is the energy change in an object, it can be calculated by using the following:
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The meaning of the word ‘work’ in physics is different from everyday use
Work is the energy change in an object, it can be calculated by using the following:
Work (J)
Displacement (m)
Force (N)
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Example 3
How much work is done if you apply a 200 N force to move a book case 4 m?
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Example 3
How much work is done if you apply a 200 N force to move a book case 4 m?