P.7.1

Question 1

what is energy

Answer 1

this is number in joules that determines what can happen

Question 2

what are the 8 energy stores

Answer 2

• chemical
• thermal
• kinetic
• gravitational / gravity
• elastic
• nuclear
• electrostatic
• magnetic

Question 3

what is an energy store

Answer 3

a store indicates how many joules of energy it can produce

Question 4

how can energy be transferred

Answer 4

• mechanically (through force)
• electrically (with a current)
  -heating by particles
  heating by radiation

Question 5

how can you work out the work done mechanically

Answer 5

work done (J) = force (N) X distance (m)

Question 6

how can you work out the energy transferred electrically

Answer 6

energy transferred (J) = electrical power (W) X time (S)

Question 7

what is the law of conservation of energy

Answer 7

energy cannot be created or destroyed it can only be transferred between stores.

Question 8

what is a closed system

Answer 8

this is when no energy or particles are lost during a reaction

Question 9

how do you analyse a situation using energy

Answer 9

• choose two points of a process
• Identify which stores have more or less energy in them at these points
• work out what type of energy transfer has occurred

Question 10

how do you analyse a situation where a constant force is involved

Answer 10

you must take into account the physical actions of the object at the two points
and the stores of energy at the two points