P2 Work, energy and power Flashcards
define work
w = fd
work = force * displacement
J
what is an energy caused due to the object’s motion
kinetic energy
what is an energy caused due to its position
potential energy
how can energy can be used to (2)
- stored
- transferred
state 5 different kinds of energy
- kinetic energy
- gravitational energy
- wind energy
- sound energy
- light energy
define kinetic energy
energy possessed by moving object
k.e = 1/2mv²
kinetic energy = 1/2 * mass * velocity squared
define gravitational energy
energy stored by objects when raised to some height above the surface of the earth
g.p.e = mgh
gravitational force = mass * gravity * height
or
g.p.e = wh
gravitational force = weight * height
how can the energy be transferred?
- forces
- waves
how can the energy be transferred?
- forces
- waves
define power
rate of doing work
p = e/t
power = energy / time
W or J/s
electricity or other useful forms of energy can be obtained by (6)
- chemical energy stored in fuel
- water, including wave energy
- geothermal resources
- nuclear fission
- heat and light from the sun
- wind energy
ad and disad of chemical energy stored in fuel
- nonrenewable
- cheap
- reliable
- global warming
ad and disad of water and hydroelectric energy
- renewable
- expensive
- reliable
- environmental damage
ad and disad of geothermal resources
- renewable
- expensive
- reliable
- heat caused
ad and disad of nuclear fission
- nonrenewable
- expensive
- environmental damage
- deforestation
