Lecture7 Ene
kin
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Yi Yelena
p
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Recall Galileo's experiment
N
demo
total energy
peg pendulum
is conserved
i
constant in
e
MF
r
ph
Ms
K
E
unit
total energy
is
Joules
depends on
system
U
t
kg m
time
r
kinetic energy t potential energy
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The notion of
force
Irest
i
comes
from energy
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apt
f Co
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Some example potentials
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a
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Earth
my
a
y
demo
vertical
cannon
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Foggia
Gmr
u
f
eg
loop the
loop
energy conservation
Emv
centripetal force
mf
Eff
HH
demo
mgh
mg
Ih
loop the loop
Wort
Let
us
define
a
useful concept
C
amount of energy transferred
to an object via a force
W
af
Fdx
Ma
d
1
initial
UCB
so
W
n
I
energy gained
e
g as kinetic
UCA
04
Ou
n
I
energy
lost
in potential
This gets
more complicated beyond one dimension
af F
W
di
yd
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Energy
and power
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over
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all solar energy received
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