Energy and the future

Question 1

what happens to energy in a energy transfer. refer to a law

Answer 1

energy is never created or destroyed. total energy before an energy transfer is the same as the total energy afterwards. the energy has just changed into one of more different forms. this is called the law of conservation of energy.

Question 2

what are the different forms of energy

Answer 2

thermal (heat), light, electrical, sound, kinetic
(movement), chemical, nuclear and potential (elastic and
gravitational)

Question 3

what is efficiency

Answer 3

the proportion of energy transferred to useful forms

Question 4

what needs to happen for a system to be at a constant temperature

Answer 4

it must be absorbing the same amount of power as it is radiating

Question 5

how does the nature of a surface affects the amount of

thermal energy radiated or absorbed

Answer 5

if a surface is black it will absorb more thermal energy than white surfaces. black surfaces will also radiate more thermal energy than white ones

Question 6

how will a system warm up

Answer 6

if the power absorbed is greater than the power radiated, it will warm up

Question 7

how will a system cool down

Answer 7

if the power absorbed is less than the power radiated, it will cool down