ch 15.1 - energy and work Flashcards
(21 cards)
what is energy?
the ability to do work
what is work?
the transfer of energy
what unit are work and energy measured in?
joules (j)
how many main forms of energy are there? what are they?
three forms - kinetic, potential, energy in fields (electromagnetic)
what is kinetic energy?
energy in motion
what does kinetic energy need?
speed and mass
kinetic energy depends on _________ more than _________.
speed more than mass
kinetic energy equation?
1/2 mv^2
what is mechanical energy?
energy associated with motion and position of everyday objects (KE + PE)
what is thermal energy?
heat - total KE and PE of all microscopic particles in an object
when atoms move faster, thermal energy…
increases
what is sound energy?
energy carried by vibrations (guitar string plucked)
what is electrical energy?
movement of electrons through a current (battery)
what is electromagnetic energy?
form of energy that travels through space in the form of waves (microwaves)
what is potential energy?
energy that is stored as a result of position/shape (book on a shelf)
what is gravitational PE?
energy that depends upon an object’s height (3m apple…)
what is elastic PE?
the PE of an object that is stretched/compressed (elastic)
what is chemical PE?
the energy stored in bonds that hold atoms together (food)
what is nuclear energy (PE)?
energy stored in an objects nucleus
fission?
nuclear fission releases energy by splitting of nuclei apart
fusion?
nuclear fusion releases energy when smaller nuclei combine to make a larger nucleus
