P1 - Energy And Energy Sources

Question 1

Energy stores

Answer 1

• thermal es (or internal es)
• kinetic es
• gravitational potential es
• elastic potential es
• chemical es
• magnetic es
• electrostatic es
• nuclear es

Question 2

How is energy transferred?

Answer 2

• mechanically (force doing work)
• electrically (work done by moving charges)
• heating
• radiation (light or sound)

Question 3

‘When a system changes, energy is transferred’

What is a system?

Answer 3

• a single object (eg air in a piston) or a group of objects (eg two colliding vehicles)
• energy can be transferred into or away from the system, between different objects in the system or between different types of energy stores
• closed systems are systems where neither matter nor energy can enter or leave. Net change in total energy is always 0

Question 4

What is work done?

Answer 4

Energy transferred
• when current flows or by a force moving on an object

Question 5

Step up transformers

Answer 5

• increase voltage
• current is reduced
• low/less energy loss to the surroundings

Question 6

Step up transformers

Answer 6

• increase voltage
• current is reduced
• low/less energy loss to the surroundings