ENERGY AND WORK Flashcards
what is energy
capacity for doing work.
what is kinetic energy
energy possessed by a moving object due to its motion
what is the kinetic energy equation
KE = 1/2 mv^2
what is potential energy
stored energy of position possessed by an object
what are the three important types of potential energy
gravitational potential energy
elastic potential energy
electric potential energy
what is gravitational potential energy
energy derived from the force of gravity
what is the equation for gravitational energy
Ep = mgh
break down the gravitational potential energy equation
m = mass
h = height
g = 9.8m/s2
does a brick on the ground have gravitational potential energy
no
does someone holding a brick in the air have gravitational potential energy
yes
what is elastic potential energy
energy stored in elastic materials as a result of their
compressing or stretching
what is the elastic potential energy equation
Ep = kx^2/2
break down the elastic potential energy equation
k = spring constant
x = displacement of spring (amount of compression)
where can elastic potential energy be stored
in rubber bands and compression springs
what is electric potential energy
energy that results from Coulomb forces associated with point charges within a defined system
what is the equation for electric potential energy
Ep = k x q1 x q2/r
breakdown the electric potential energy equation
k = 8.99 x 19 NM2/C2
q1 and q2 are charges
r = distance between two charges
what is the coloumb constant
k = 8.99 x 19 NM2/C2
why is a negative sign assigned to electric potential energy answers
there is an attractive force between them.
what is work
transfer of energy by a force
all work is also equated to what
all work is energy transfer.
what is work measured in
joules
what is the equation calculating the amount of work produced by a force
Work = F.d.cosθ
what is energy and work measured in
Both energy and work are measured in joules
how is 1J of work equal to in energy
1 J = 1N x 1m
what is mechanical energy
sum of the kinetic energy (Ek) and potential energy (Ep)
what is the mechanical energy equation
ET = Ep + Ek
describe ep and ek in an isolated system
sum of the kinetic and potential energy will remain the same, although the kinetic energy and potential energy may vary
what is power
rate at which work is done
what is power units
watts
what is watts also equal to
joules/second (J/S).
what is the power equation
p = w/t
work/time
work is joules
time is seconds
