Law of Conservation of Energy
What is the definition of the law of conservation of energy
energy can neither be created nor destroyed by transferred from one form to another
What is potential energy
stored energy
what is kinetic energy?
moving or motion
what is the formula for efficiency?
useful energy/input energy x 100
what are the two categories of energy
kinetic and potential
Heat
what is the position where the potential energy is at its lowest
the bottom
a person running is using _________ energy?
kinetic
draw an energy chain for a roller coaster with one high point
potential -> kinetic -> gravitational potential -> kinetic + heat + sound
what type of heat transfer happens in solids?
conduction
What is the type of energy that is stored in food and is the enrgy of molecular bonds
chemical
a compressed spring has what type of energy?
elastic potential energy
a ball gets pushed off a table. what type of energy does it have?
kinetic
if a 400W light bulb is 50% efficient, what does that mean?
that means that 200W is being used for light and 200W is lost to heat
as a liquid is heated, what do the particles do?
move faster and expand (move further apart)
What is energy measured in?
Joules (or Kilojoules)
A ball sits on a table. What type of energy does it have?
gravitational potential energy
True False
kinetic energy can be converted to gravitational potential, heat, light and sound.
true
electrical
why is the term "don't let the cold air in" incorrect?
hot will travel from hot to cold so the hot air will travel to the outside
How many Joules are in a Kilojoule
1000J = 1KJ
which has more potential energy?? an empty plane or a full plane? (both are flying)
full plane (it's heavier)
the bigger the objects mass the greater the __________ energy
kinetic
what would be the output of a stretched rubber band?
elastic potential
what colour absorbs heat best?
dark colours