Energy Topic Flashcards
What are the eight energy stores.
Thermal
Kinetic
Gravitational potential
Elastic potential
Chemical
Magnetic
Electromagnetic
Nuclear
What is the word that describes the transferred energy
Work done
What are the 4 ways that energy can be transferred?
Mechanically (force)
Electrically (moving charges)
Heating
Radiation (light / sound)
What are you doing when you apply a force to a spring
You are applying “work”. _ we are putting energy into a spring to stretch it. The stretched spring is storing the energy and it is called elastic potential.
What is extension in a spring)
The extension is how much the length has changed from its original form. (Spring)
What is the the symbol for extension in equations?
e (lowercase)
What is the extension measured in?
Metres
What is the realisation ship between force and extension?
They are directly proportional to each other except when the spring has too much force acting on it and the spring stretches too far and reaches its limit of proportionality - at this point when the force is removed the spring will not go back to its original form.
What is the equation for elastic potential energy?
Ee = 0.5 x k x e(squared)
What is k in the elastic potential equation?
Spring constant
What is the spring constant measured in
N/m
What is gravitational potential energy?
The energy stored in an object due to its position above the earths surface. This is due to the force of gravity acting on an object
What is the equation for gravitational potential energy?
Ep = m x g x h
Energy = mass (kg) x gravitational field strength (N/kg) x height (m)
What is the mass measured in (GPE)
Kg
What is the height measured in (GPE)
m
what is kinetic energy?
The energy stored in moving objects . Stationary objects don’t have any
What is the equation for kinetic energy?
Ek = 0.5 x m x v(squared)
Kinetic energy = 0.5 x mass x speed squared
What is the mass measured in (K)
Kg
What is speed measured in?
M/s
What is specific heat capacity?
The SHC of a substance is the amount of energy required to raise the temperature of 1kg of the substance by 1 degrees C
How do you work out the change in thermal energy?
<E = m x c x <0
Change in thermal energy = mass x specific heat capacity x temperature change
(< is meant to be a triangle)
What does efficiency tell us about an appliance
What percentage of the input energy is being used as useful output energy
What is the equation for efficiency?
Useful power output divided by the total power input
If the question asks for a percentage times this by 100
