4 Energy resources and energy transfers
The following sub-topics are covered in this section.
(a) Units
(b) Energy transfers
(c) Work and power
(d) Energy resources and electricity generation
(a) Units
4.1 use the following units:
kilogram (kg)
joule (J)
metre (m)
metre/second (m/s)
metre/second 2 (m/s2)
newton (N)
second (s)
watt (W)
(b) Energy transfers
4.2 describe energy transfers involving energy stores:
1. Kinetic store
2. Gravitational Potential store
3. Chemical store
4. Elastic Potential store
5. Magnetic store
6. Electrostatic store
7. Nuclear store
8. Thermal store
KG CEMENT
Total Useful energy in -> MACHINE -> useful energy out
+ waste energy
, • energy transfer mechanisms:
● mechanically (forces)
● electrically (electricity)
● by heating
● by radiation (light and sound)
Often go out into surroundings
HERM
Heat is linked to the kinetic energy of a particle. The more they move the hotter the object. This is
why heat causes changes in states.
The temperature of an object is its average kinetic energy of the particles. The heat is the total
kinetic energy of all the particles.
Iceberg is hotter than flamme as has more particles.
4.3 use the principle of conservation of energy
Energy (stores) is never created or destroyed. only transferred from one store to another via a
transfer mechanism .
Total energy at the start must equal energy at the end.
4.4 know and use the relationship between efficiency, useful energy output and total energy
output:
[X 100 to get percentage]
The following sub-topics are covered in this section.
(a) Units
(b) Energy transfers
(c) Work and power
(d) Energy resources and electricity generation
(a) Units
4.1 use the following units:
kilogram (kg)
joule (J)
metre (m)
metre/second (m/s)
metre/second 2 (m/s2)
newton (N)
second (s)
watt (W)
(b) Energy transfers
4.2 describe energy transfers involving energy stores:
1. Kinetic store
2. Gravitational Potential store
3. Chemical store
4. Elastic Potential store
5. Magnetic store
6. Electrostatic store
7. Nuclear store
8. Thermal store
KG CEMENT
Total Useful energy in -> MACHINE -> useful energy out
+ waste energy
, • energy transfer mechanisms:
● mechanically (forces)
● electrically (electricity)
● by heating
● by radiation (light and sound)
Often go out into surroundings
HERM
Heat is linked to the kinetic energy of a particle. The more they move the hotter the object. This is
why heat causes changes in states.
The temperature of an object is its average kinetic energy of the particles. The heat is the total
kinetic energy of all the particles.
Iceberg is hotter than flamme as has more particles.
4.3 use the principle of conservation of energy
Energy (stores) is never created or destroyed. only transferred from one store to another via a
transfer mechanism .
Total energy at the start must equal energy at the end.
4.4 know and use the relationship between efficiency, useful energy output and total energy
output:
[X 100 to get percentage]
