study checklist

Question 1

list the different types of energy

Answer 1

kinetic, sound, heat, elastic potential, chemical potential, gravitational potential, electric

Question 2

state the law of conservation of energy

Answer 2

energy cannot be created or destroyed, it can only be transferred or transformed

Question 3

what is the formula for calculating Ek

Answer 3

Ek= 1/2 m v^2

Question 4

what is the formula for calculating Ep

Answer 4

Ep=mgh

Question 5

define work, state formula

Answer 5

work is an objects change of energy due to external forces. W= Fd
it is measured in Joules

Question 6

define power, state formula

Answer 6

power is the rate of doing work.
P= W/(delta)t
it is measured in Watts

Question 7

identify useful and unhelpful forms of energy in specific applications

Answer 7

an example of useful energy would be the light emitting a torch when in use, unhelpful would be the warmth radiating the torch after long use.

Question 8

explain efficiency and how to calculate it

Answer 8

efficiency is the percent of how much useful energy the product uses to generate results.
useful energy output/total energy input x 100%

Question 9

state the SI units for energy/work, distance, time, force, power, mass.

Answer 9

energy/work= Joules, J
distance= metres, m
time= seconds, s
force= Newtons, N
power= Watts, W
mass= kilograms, kg