physics chaopet 1
tyoes if enegry stores
chemical, elastic, themral, magnetic, nuclear, gpe, kinetic, electrical, sound, light, mechanical
conservationof enery
no enery gets destoryed and no energy gets created
system
collection of objects that can be identified
closed system
an isolated system; no energy comes in or gets out
pendulum
a= max gpe
a-b= gpe down, kinecti up
b= kinecti
b-c= kinetic down, gpe up
c= gpe
bungee jumping
beofr jimping = max gpe
as u jump and fall = kinetic up gpe down
falling= kinetic, gpe downnn
rope recoiling= elastic up, kinetic down, gle.up
coming bakc up= elastic, gpe up, kinetic down
bunge
force of rope reduces speed of jumper
rope recoils n pula jumoer back up
work work work work work
work done = energy transferred
work= f×d
joules
force is newrotns
distance is metres
friction
frictoo converts kinine5ic enegry to thermal
rubbing ur hands cogousoglu
the muscles in ur hand do work to ivercome, work done trnasfwrs energy kinetic energy which then transfers thermal energy because of friction
brake pads
kinrtoc energy of vehicle trnasfers to thermal because of the friction vetween the brake pads and wheel discs
metoriws
the meteorites gpe transfers to kinetic to thermal bevause of friction against it caused ny air resistsntacne
gpe
the energy an objevt stores bcs if its positio
ep
ep= mgh
measure in ju
oules
kinetic energy
the energy an object stores because its moving
ek
ek=1/2mv²
m=ek÷.5v²
v²= ek÷.5m
ee
ee=1/2ke²
k=ee÷.5e²
hookes law
f=ke where k is the spring constant
extension
final length - original length
slring constabt
a measure of how strong a spring is
disspiraiton
spreading iut
useful energy
energy transferrred in the place we want it and the form we need it
watsed energy
energy that isnt usefully transferrred and is undesired
disspurpatioj eule
watsrd neegy js didspitatd
useful energy is eventually disspitauted
wnergy becomes less useful the more it dissipates
wffiency
useful enrgy÷total×100
no unit
input enrgy
energy supplied to the devide
total input enery formual
usdufl energy+wasted energy
clockwork radio
when u turn a handle, u wind up a spring and increase ee. when the spring unwinds, its energy is trnasferred to kinetic and it turns a small eletric generator
choosing an electric appliance
hsould waste as less energy as possbike
what energy do we use most
electricity, gas, oil
uses of everyday elecvruricyut
lighting, heating, making objects move by using an electric motor, producing sound and visula images
power=
rate of trandfer of energy
meaudted in watts
= e/t
e= pt
t= e/p
1kw
1,000 watts
1mw
1,000,000 watts
wated power
total-useful power in
hr to s
×3600
m to s
×60