conservation and dissipation of energy Flashcards
(26 cards)
what is chemical energy?
energy transferred during chemical reactions
What is kinetic energy?
energy an object has beacsue it is moving
what is gravitattional potential energy?
Energy stored an object has due to its position above the Earth’s surface.
what is elastic potential energy?
Energy stored in stretched or compressed objects
What is nucleur energy?
Energy stored in the nucleus of an atom
What is eletrical energy?
Energy of moving electrons
What is light energy?
Energy of electromagnetic waves
how is energy transferred?
by eletric current or force or waves
What are the rules of energy?
energy cannot be created or destroyed only trasnaferred.
What is work done?
amount of energy transferred from an object
What is the equasion for work done?
w = force applied x distance moved
( j) ( n) ( m)
What is the equasion for the change in gravitational potential energy?
weight x change of height
( n) ( m)
When does the gravitational potential energy store of an object increase?
increases when it moves up and decreases when it moves down.
What is the equasion for kinetic energy?
kinetic energy
= 1/2 x mass x speed(squared)
(kg) (m/s)
What is the equation to calculate elastic potential energy?
elastic potential energy = 1/2 x spring constant(n/m) x
extension(squared)
(m squared)
What is useful energy?
energy which is required for an object to work.
What is wasted energy?
energy that is not usefully transferred.
What happens when energy dissipates?
it gets less useful
how to work out the efficinecy of a device?
useful energy transferred by device (j)/ total energy supplied to the device (x 100%)
How to work out input energy?
useful output energy + energy wasted
Can eletrical appliances transfer energy?
yes in the form of useful energy at the flick of a switch.
What is the equation for power?
energy trasnferred to appliance (j) /
time take for energy to be trasnferred (s)
What is power?
energy transformed or transferred per second. (watts)
What is the equation for power wasted by an appliance?
total power input - useful power output
