How can we describe motion in terms of energy transfers?Energy transfers
Energy stored in a moving object is called kinetic energy. As an object is raised above ground its gravitational potential energy increases. When a force moves an object work is done.
There are energy transfers going on all the time - whenever a systemAn object or group of objects. changes there is a change in the way some or all of the energy is stored.
Kinetic energy is transferred into gravitational potential energy.
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Climbing stairs
Chemical energy in muscles is transferred to gravitational potential energy as someone climbs the stairs.
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Two bodies colliding
Kinetic energy transfers to heat and sound as two bodies collide.
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Slide1 of 3, Boat suspended from column, swings in circular arc. Highest point: no kinetic energy, max gravitational potential energy. Lowest point: max kinetic energy, minimum gravitational potential energy., A swinging pirate ship ride at a theme park. Kinetic energy is transferred into gravitational potential energy.
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Transferring energy
Energy is transferred by one of the following four types of energy transfer:
mechanical work – a force moving an object through a distance
electrical work – charges moving due to a potential difference
heating – due to temperature difference caused electrically or by chemical reaction
radiation – energy transferred as a wave, eg light, infrared, sound - light radiation and infrared radiation is emittedEnergy is 'given-out' by the material and the internal energy of the material will decrease. For example, infrared radiation from the Sun is emitted into space. by the Sun.
Doing 'work' is the scientific way of saying that energy has been transferred. For example, a grazing cow, a firing catapult and a boiling kettle are all doing 'work', as energy is being transferred.