Mathematics
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OpenStudy (anonymous):
@Outkast3r09
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OpenStudy (anonymous):
i see boxes =P
OpenStudy (anonymous):
Mechanical energy
vertical displacent
energy
OpenStudy (anonymous):
umm? ok question?
OpenStudy (anonymous):
I've been up since 5 am :'( can't think anymore.
what happens to energy in this situation?
OpenStudy (anonymous):
now we have potential energy correct?
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OpenStudy (anonymous):
V?
OpenStudy (anonymous):
mgh?
OpenStudy (anonymous):
E= U + K
OpenStudy (anonymous):
\[\frac 12 mv^2\]
OpenStudy (anonymous):
C=Q/V?
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OpenStudy (anonymous):
what do you mean?
OpenStudy (anonymous):
what happens to the energy in terms of mechanics?
OpenStudy (anonymous):
yes
OpenStudy (anonymous):
well lets see it starts with a potential energy and no kinetic
OpenStudy (anonymous):
we're only looking at it before and after it finished moving, so:
no K I think
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OpenStudy (anonymous):
so what happened to the energy you are trying to ask?
OpenStudy (anonymous):
since you end up with no kinetic or potential?
OpenStudy (anonymous):
oh it's lifting the object
OpenStudy (anonymous):
yes
OpenStudy (anonymous):
sorry
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OpenStudy (anonymous):
the capacitor i'm assuming is using the energy to do work , and potential
OpenStudy (anonymous):
sounds right
OpenStudy (anonymous):
so
C=Q/V
voltage from where? battery? outlet?
OpenStudy (anonymous):
yes battery
OpenStudy (anonymous):
where rae you getting it? lol outlet and battery are different lol
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OpenStudy (anonymous):
alright
OpenStudy (anonymous):
I guess I have to relate
\[C=QV\]
to
\[U=\frac 12 CV^2\]
to \[mgh\]
what are we solving for?
the displacement?
OpenStudy (anonymous):
we know V
\[mgh=\frac 12 CV^2\]
we know mg and V
OpenStudy (anonymous):
how can we get C?
where is work? LOL
OpenStudy (anonymous):
what about work?
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OpenStudy (anonymous):
\[W=\int F\cdot dr\]
or E dr
OpenStudy (anonymous):
would work be electrical in this case though since it's mechanical work?
OpenStudy (anonymous):
sure
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OpenStudy (anonymous):
is that yes or no lol
OpenStudy (anonymous):
yes?
OpenStudy (anonymous):
potential energy
OpenStudy (anonymous):
So what is the actual question... i haven't actually gotten a question.. I've gotten 2 formulas and a procedure it sounds like lol
OpenStudy (anonymous):
also dr = h
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OpenStudy (anonymous):
;)
OpenStudy (anonymous):
W=Fd=Fh
\[mgh+Fh=
OpenStudy (anonymous):
\[h(mg+F)\]?
OpenStudy (anonymous):
we dont have to integrate i'm assuming
OpenStudy (anonymous):
no it's straight up
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OpenStudy (anonymous):
alright
OpenStudy (anonymous):
now we need the work done
OpenStudy (anonymous):
?
OpenStudy (anonymous):
yes isn't that what it's asking lol
OpenStudy (anonymous):
so you're lifting the mass meaning there is work being done = energy being used to lift it
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OpenStudy (anonymous):
I'm tired dude....
ok so we used up E
OpenStudy (anonymous):
E= U+0
OpenStudy (anonymous):
ok so E is actually your capacitor right?
OpenStudy (anonymous):
I hope so....let's say it is
OpenStudy (anonymous):
Alright so E is equation 24-8 in page you showed me
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OpenStudy (anonymous):
since
\[E_1=E_2\]
\[E_1=mgh+\frac{1}{2}mv^2+U_c\]
OpenStudy (anonymous):
\[mg(0)+\frac{1}{2}m(0^2)+U_c\]
OpenStudy (anonymous):
so all energy is coming from the capacitor
OpenStudy (anonymous):
now the other side you have
\[mgh+\frac{1}{2}mv^2+W_{app}+W_d\]i'm assuming drag will be really low so it's not taken into account
OpenStudy (anonymous):
what's W app? and W d?
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OpenStudy (anonymous):
but since we're looking at it at rest in two places you have
\[mgh+0+Fh\]
\[U_c=mgh+Fh=(mg+F)h\]
OpenStudy (anonymous):
this is what i'm thinking but i'm only like 50% certain lol
OpenStudy (anonymous):
if it isn't that much don't worry about it
OpenStudy (anonymous):
\[F=ma\]
\[(mg+ma)h=(m(g+a))h\]
OpenStudy (anonymous):
\[\frac{U_c}{m(g+a)}=h\]
maybe!?!?!?! lol
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OpenStudy (anonymous):
W_d is work done by the drag force... which is going to be nothing probably since the velocity will be minimal
OpenStudy (anonymous):
that's sort of a toughie question... we haven't gotten to capacitors and such yet