Energy Stores and Transfers Flashcards
When work is done what happens to energy?
Energy gets transferred (mechanically) from one store to another
What is the relationship between energy transferred and work done?
Energy transferred (J) = Work done (J)
What happens if a force acts in the direction of an object’s movement?
The object gains energy, usually kinetic energy
What happens if a force acts opposite to an object’s movement?
The object loses energy, usually heat
When is work being done on an object?
When a force moves an object in the same direction as the force applied
What happens if a force is applied but the object doesn’t move?
No work is done
What is the equation for work done?
Work done = Force x Distance
J = N x M
What is the units for the equation for work done?
- Work done: Joules (J) or Newton-meter (N·m)
- Force: Newtons (N)
- Distance: Meters (m)
What is the doing work and measuring work experiment?
- Drag the block a measured distance using the newton meter, trying to keep the force constant
- Record the distance and the force
- Repeat steps 1 and 2 at least twice more, keeping the distance the same each time
- Wrap 2 elastic bands around the block and repeat steps 1 and 2 with the elastic bands, keeping the distance the same each time
What was the effect of the elastic bands in the experiment?
More work was needed with the elastic bands because they created more friction.
What were the variables in the experiment?
- Independent Variable: Elastic band
- Dependent Variable: Force
- Control Variable: Wooden block
How many energy transfers are there?
4
How many energy stores are there?
8
Name the 8 energy stores
- Elastic
- Magnetic
- Kinetic
- Gravitational
- Chemical
- Electrostatic
- Thermal
- Nuclear
Name the 4 energy transfers
- Electrically
- Mechanically
- By radiation
- By heating
Describe the magnetic energy store and give examples
Stored when like poles are pushed together or opposite poles are pulled apart.
e.g. Fridge magnets / Compasses
Describe the internal (thermal) energy store and give examples
The total kinetic and potential energy of particles in an object; in hotter objects, particles move faster.
e.g. Stoves or hobs / Human bodies
Describe the chemical energy store and give examples
Stored in chemical bonds between molecules.
e.g. Foods / Electrical cells
Describe the kinetic energy store and give examples
The energy of a moving object.
e.g. Buses / Runners
Describe the electrostatic energy store and give examples
Stored when like charges are pushed together or opposite charges are pulled apart.
e.g. Thunder clouds
Describe the elastic potential energy store and give examples
Stored when an object is stretched or compressed.
e.g. Compressed springs
Describe the gravitational potential energy store and give examples
Stored in objects due to their height above the ground.
e.g. Aeroplanes
Describe the nuclear energy store and give examples
Energy stored in the nucleus of an atom.
e.g. Nuclear reactors
