Difference between revisions of "Energy Transfer"
(→Going Up) |
(→Real World Energy Transfers) |
||
| Line 32: | Line 32: | ||
: When an [[object]] travels upwards the [[Gravitational Potential Energy Store|gravitational potential energy store]] increases. | : When an [[object]] travels upwards the [[Gravitational Potential Energy Store|gravitational potential energy store]] increases. | ||
The following are examples of '''energy transfers''' into the [[Gravitational Potential Energy Store|gravitational potential energy store]]: | The following are examples of '''energy transfers''' into the [[Gravitational Potential Energy Store|gravitational potential energy store]]: | ||
| − | *A ball starts in motion but comes to rest at its maximum height. | + | *A ball starts in motion but comes to rest at its maximum height. [[Mechanical Energy Transfer|Mechanical energy transfer]] due to the [[force]] of [[weight]]. |
''[[Kinetic Energy Store]] of the ball → [[Gravitational Potential Energy Store]] of the ball.'' | ''[[Kinetic Energy Store]] of the ball → [[Gravitational Potential Energy Store]] of the ball.'' | ||
| − | *A firework is fired upwards and comes to rest at its maximum height. | + | *A firework is fired upwards and comes to rest at its maximum height. [[Mechanical Energy Transfer|Mechanical energy transfer]] due to the [[force]] of [[weight]]. |
''[[Chemical Potential Energy Store]] of the gunpowder → [[Gravitational Potential Energy Store]] of the firework.'' | ''[[Chemical Potential Energy Store]] of the gunpowder → [[Gravitational Potential Energy Store]] of the firework.'' | ||
| − | *An arrow is fired upwards and comes to rest at its maximum height. | + | *An arrow is fired upwards and comes to rest at its maximum height. [[Mechanical Energy Transfer|Mechanical energy transfer]] due to the [[force]] of the bow on the arrow and the [[weight]] of the arrow. |
''[[Elastic Potential Energy Store]] of the bow → [[Gravitational Potential Energy Store]] of the arrow.'' | ''[[Elastic Potential Energy Store]] of the bow → [[Gravitational Potential Energy Store]] of the arrow.'' | ||
====Falling==== | ====Falling==== | ||
: When an [[object]] falls the [[Gravitational Potential Energy Store|gravitational potential energy store]] decreases. | : When an [[object]] falls the [[Gravitational Potential Energy Store|gravitational potential energy store]] decreases. | ||
| − | *A ball is dropped and after bouncing a few times it comes to rest. | + | *A ball is dropped and after bouncing a few times it comes to rest. [[Mechanical Energy Transfer|Mechanical energy transfer]] due to the [[force]] of [[weight]]. |
| − | [[Gravitational Potential Energy Store]] of the ball → [[Thermal Energy Store]] of the ball and surroundings | + | ''[[Gravitational Potential Energy Store]] of the ball → [[Thermal Energy Store]] of the ball and surroundings'' |
| − | *A trampolinist stars at a height of 2 metres and falls onto a trampoline stretching the springs. | + | *A trampolinist stars at a height of 2 metres and falls onto a trampoline stretching the springs. [[Mechanical Energy Transfer|Mechanical energy transfer]] due to the [[weight]] of the trampolinist and the [[force]] needed to extend the springs. |
| − | [[Gravitational Potential Energy Store]] of the trampolinist → [[Elastic Potential Energy Store]] of the trampoline. | + | ''[[Gravitational Potential Energy Store]] of the trampolinist → [[Elastic Potential Energy Store]] of the trampoline.'' |
| + | |||
| + | ====Collisions==== | ||
| + | : When an [[object]] [[collide]]s with another [[object]] [[energy]] the [[Kinetic Energy Store|kinetic energy store]] of the first [[object]] decreases. | ||
| + | *A white ball hits a red ball on a snooker table. [[Mechanical Energy Transfer|Mechanical energy transfer]] due action [[force]] and reaction [[force]] between the two [[object]]s. | ||
| + | ''[[Kinetic Energy Store]] of the white ball → [[Kinetic Energy Store]] of the red ball.'' | ||
| + | *A tennis ball in collision with a wall. [[Mechanical Energy Transfer|Mechanical energy transfer]] due action [[force]] and reaction [[force]] between the two [[object]]s. | ||
| + | ''[[Kinetic Energy Store]] of the tennis ball → [[Elastic Potential Energy Store]] of the tennis ball.'' | ||
| + | *A sponge in collision with a wall. [[Mechanical Energy Transfer|Mechanical energy transfer]] due action [[force]] and reaction [[force]] between the two [[object]]s. | ||
| + | ''[[Kinetic Energy Store]] of the sponge → [[Thermal Energy Store]] of the sponge and surroundings.'' | ||
| + | |||
| + | ====Acceleration by a Constant Force==== | ||
| + | : When an [[object]] [[accelerate]]s the [[Kinetic Energy Store|kinetic energy store]] increases. | ||
| + | *A car [[accelerate]]s from rest. [[Mechanical Energy Transfer|Mechanical energy transfer]] due to [[Driving Force|driving force]]. | ||
| + | ''[[Chemical Potential Energy Store]] of the [[fuel]]/[[battery]] → [[Kinetic Energy Store]] of the [[car]].'' | ||
| + | *A skydiver [[accelerate]]s to [[Terminal Velocity|terminal velocity]] after jumping out of a plane.[[Mechanical Energy Transfer|Mechanical energy transfer]] due to the [[force]] of [[weight]]. | ||
| + | ''[[Gravitational Potential Energy Store]] of the skydiver → [[Kinetic Energy Store]] of the skydiver.'' | ||
| + | |||
| + | ====A vehicle slowing down==== | ||
| + | : When an [[object]] [[decelerate]]s the [[Kinetic Energy Store|kinetic energy store]] decreases. | ||
| + | *A car applies the brakes. [[Mechanical Energy Transfer|Mechanical energy transfer]] due to [[friction]]. | ||
| + | ''[[Kinetic Energy Store]] of the [[car]] → [[Thermal Energy Store]] of the brakes.'' | ||
| + | *A ball rolls before coming to a stop. [[Mechanical Energy Transfer|Mechanical energy transfer]] due to [[friction]]. | ||
| + | ''[[Kinetic Energy Store]] of the ball → [[Thermal Energy Store]] of the ball and surroundings.'' | ||
| + | |||
| + | ====Heating==== | ||
| + | : When [[object]]s are [[heat]]ed the [[Thermal Energy Store|thermal energy store]] or the [[Internal Energy]] of the [[object]] increases. | ||
| + | *A water filled kettle is placed on a stove. [[Heating|Energy Transfer by Heating]] due to the stove being a higher [[temperature]] than the kettle. | ||
| + | [[Thermal Energy Store]] of the stove → [[Thermal Energy Store]] of the [[water]] and kettle. | ||
| + | *An electric kettle is connected to a car [[battery]]. [[Electricity|Electrical Energy Transfer]] due to the [[Electrical Current|current]] flowing from the [[battery]] to the kettle. | ||
| + | [[Chemical Potential Energy Store]] of the [[battery]] → [[Thermal Energy Store]] of the [[water]] and kettle. | ||
===Examples=== | ===Examples=== | ||
Revision as of 15:01, 2 February 2019
Contents
Key Stage 3
Meaning
An Energy Transfer is when energy moves from one energy store to another energy store.
About Energy Transfers
- Energy can be transferred from one object to another or between energy stores within the same object. For example on a pool table when white ball hits another ball energy is transferred from the kinetic store of the white ball to the kinetic store of the other ball.
There are 4 ways energy can be transferred;
- Mechanically - By the action of a force.
- Electrically - By an electrical current.
- By radiation - By Light waves or Sound waves.
- By heating - By conduction, convection or radiation.
Key Stage 4
Meaning
An Energy Transfer is when energy moves from one energy store to another energy store.
About Energy Transfers
- Energy and be transferred between stores in a system. This may be between the different energy stores of a single object or between the energy stores of different objects within that system.
- When there is an energy transfer energy is neither created, nor destroyed. This means when that when one energy store decreases, one or more others must increase.
- Humans use energy transfers for a number of reasons but they usually result in some energy being transferred to an unwanted store. This is known as Wasted Energy.
There are 4 ways energy can be transferred;
- Mechanically - By the action of a force.
- Electrically - By an electrical current.
- By radiation - By Light waves or Sound waves.
- By heating - By conduction, convection or radiation.
Real World Energy Transfers
When describing the energy transfers in a system the initial energy store and final energy store are stated. NB: It is important to note which object has the energy store. It is not enough to say a "Thermal Energy Store", it must be a "Thermal Energy Store of the object".
Going Up
- When an object travels upwards the gravitational potential energy store increases.
The following are examples of energy transfers into the gravitational potential energy store:
- A ball starts in motion but comes to rest at its maximum height. Mechanical energy transfer due to the force of weight.
Kinetic Energy Store of the ball → Gravitational Potential Energy Store of the ball.
- A firework is fired upwards and comes to rest at its maximum height. Mechanical energy transfer due to the force of weight.
Chemical Potential Energy Store of the gunpowder → Gravitational Potential Energy Store of the firework.
- An arrow is fired upwards and comes to rest at its maximum height. Mechanical energy transfer due to the force of the bow on the arrow and the weight of the arrow.
Elastic Potential Energy Store of the bow → Gravitational Potential Energy Store of the arrow.
Falling
- When an object falls the gravitational potential energy store decreases.
- A ball is dropped and after bouncing a few times it comes to rest. Mechanical energy transfer due to the force of weight.
Gravitational Potential Energy Store of the ball → Thermal Energy Store of the ball and surroundings
- A trampolinist stars at a height of 2 metres and falls onto a trampoline stretching the springs. Mechanical energy transfer due to the weight of the trampolinist and the force needed to extend the springs.
Gravitational Potential Energy Store of the trampolinist → Elastic Potential Energy Store of the trampoline.
Collisions
- When an object collides with another object energy the kinetic energy store of the first object decreases.
- A white ball hits a red ball on a snooker table. Mechanical energy transfer due action force and reaction force between the two objects.
Kinetic Energy Store of the white ball → Kinetic Energy Store of the red ball.
- A tennis ball in collision with a wall. Mechanical energy transfer due action force and reaction force between the two objects.
Kinetic Energy Store of the tennis ball → Elastic Potential Energy Store of the tennis ball.
- A sponge in collision with a wall. Mechanical energy transfer due action force and reaction force between the two objects.
Kinetic Energy Store of the sponge → Thermal Energy Store of the sponge and surroundings.
Acceleration by a Constant Force
- When an object accelerates the kinetic energy store increases.
- A car accelerates from rest. Mechanical energy transfer due to driving force.
Chemical Potential Energy Store of the fuel/battery → Kinetic Energy Store of the car.
- A skydiver accelerates to terminal velocity after jumping out of a plane.Mechanical energy transfer due to the force of weight.
Gravitational Potential Energy Store of the skydiver → Kinetic Energy Store of the skydiver.
A vehicle slowing down
- When an object decelerates the kinetic energy store decreases.
- A car applies the brakes. Mechanical energy transfer due to friction.
Kinetic Energy Store of the car → Thermal Energy Store of the brakes.
- A ball rolls before coming to a stop. Mechanical energy transfer due to friction.
Kinetic Energy Store of the ball → Thermal Energy Store of the ball and surroundings.
Heating
- When objects are heated the thermal energy store or the Internal Energy of the object increases.
- A water filled kettle is placed on a stove. Energy Transfer by Heating due to the stove being a higher temperature than the kettle.
Thermal Energy Store of the stove → Thermal Energy Store of the water and kettle.
- An electric kettle is connected to a car battery. Electrical Energy Transfer due to the current flowing from the battery to the kettle.
Chemical Potential Energy Store of the battery → Thermal Energy Store of the water and kettle.
Examples
 |
 |
| The front brakes of this car are glowing from the high temperature. Energy has been transferred by friction from the Kinetic Energy Store of the car to the Thermal Energy Store of the brakes.
The high temperature of the brakes causes them to heat the air around them. Energy is being tansferred by heating from the Thermal Energy Store of the brakes to the Thermal Energy Store of the air around them. |
Electricity transfers energy into the Thermal Energy Store of the filament inside the bulb.
The high temperature causes the bulb to glow, emitting Visible Light. This Visible Light transfers energy by radiation to the surroundings. |