P1:Conservation and dissipation of energy Flashcards
The 8 energy stores:
-Magnetic
- Kinetic
-Thermal
-Chemical
-Gravitational
-Electrical
-Nuclear
-Elastic
How does energy move from one store to another?
Transfers
How can energy be transferred?
-Heating
-Waves
-Force when it moves an object.
When an object falls and speeds up, what happens to it’s energy stores?
-Increase in kinetic
-Decrease in graviational
What is the principle of conservation of energy?
energy cannot be created or destroyed.
What is a closed system?
a system in which no energy transfers take place out of or into the system.
What is energy transferred also known as?
Work done
equation for work done:
force applied (N) x Distance moved (m)
When trying to overcome friction, which energy store does it transfer to?
Thermal
Where can chemical energy stores be found in humans?
Our muscle
The force you need to lift an object at constant velocity is equal and opposite to:
the gravitational force on the object.
The work done when an object moves up or down depends on:
-change in height
-weight
equation of gpe
mass x gfs x change in height
what is kinetic energy?
energy of movement
equation of kinetic energy:
1/2 x mass x speed (squared)
What energy store is transferred to when you stretch an rubber band?
elastic potential energy
What is Hooke’s Law?
Force =k(spring constant) x extension.
equation for elastic potential energy:
1/2 x spring constant x extension (squared)
What is useful energy?
energy transferred to where it is wanted the way that it is wanted
what is wasted energy?
energy that is not usefully transferred
scientific word for spread out:
dissipated
example of dissipation of wasted energy
plane taking off, energy transferred from engines chemical energy into kinetic and gravitational
what causes some energy to be wasted?
friction
what is given out when wasted energy is dissipated
thermal energy
