here you see
topics that will be covered by his exam
flight as much material as last time
and of course the material is also more
difficult
i will touch upon most of these topics
today not all
and i can't go
into great depth
for obvious reasons we don't have the
time
i want to emphasize that what is not
cover today
does not mean it all that it will not be
on the exam
i won't want to ask your attention fort
the storm
key concepts
we were going to be theorem
would tell you that isn't even object
moves from a to b
at the work done on that all jacked
kinetic energy at point b_ minus two
connecticut internet porn eight
is always a plus
conservative forces like gravitational
in spring forces but it also
hold sport
not a conservative forces
such as flexion
flexion can remove
connecticut reggie
it don't really get into heat
and that is perfectly fine into work and
i just feel
however the conservation of mechanical
energy
only holds for conservative forces
there you have
the conservation of the summer potential
energy and connecticut
and now of course you cannot afford
to loose conn of youth week
then the
cultivation of mechanical energy
would not hold and so that can only be
used exclusively indicates
of conservative forces
that starts
with a simple example
all pay incline
at an angle fayda
i have your object
mass and
friction coefficient connecticut new j
and the static friction coefficient
equals
u_s_
this point here that kept me point eight
and that i bought ample inclined to be
and
distance between them
along the slope yeah
and the first thing that you want to do
with it
problem like this
you want to make would be called a free
bowie diagram
that means you want to go all the forces
all metal
clearly there is gravity which is angie
and then
there is the normal force perpendicular
to the surface
surface pushes up
recalled its
normal force
object wants to slide down
friction holds it up
tornadoes also
a fictional
and these are the only three forces
that are on it so we're free bodyguard
and you won't know more
however
i wanted to appreciate the fact
that deforrest from the surface
on to dissolve the active is of course
defect or ill some between these two
and that is what's called normally the
contact sports
and that contact forced better the
exactly at the same as and g but the
opposite direction otherwise it would
never be delivery
of course we always split it into
perpendicular directions
because of the way that green analyze
this there's no acceleration in the
wider action
only indeed
x evacuated starts moving and that's why
we split but of course
effect a real some
is really the
force which meets the surface potions
onto that object
all right let's suppose nagad we
increase the angle theta
until the object
starts to slide
so no i'm going to decompose these
forces
any extra rection i have here and jean
science data
and the component office
gravity
in the white election equals angie
course i think i think there's no
acceleration in the white election
the normal force
must be also m_g_
or something up
alright lifted up his inclined to the
point that it is just about to start
sliding
and so
that means that the frictional forces
is a maximum value possible
which is the static friction
coefficients
and therefore that is
you address times and g
funds to co-sign all data
and when will that happen
when the fictional force and angie
site data are exactly the equal if i go
down one higher further it will start to
flight
and so that's the case
when these people engine
klein data
and so you lose you and g
and you find
u_s_
equals
tend to fade out that when it will
happen
this is a way that you can measure the
static friction coefficient
alternatively if you notice static
friction coefficient
you can predict what angle
that real popular
at that situation that
it's just
hanging
bike week bomb so to speak bites
fingernails
retouching very likely will bow on it
and it starts to slide
and now i'm interested in knowing what
the acceleration is downhill
the reason why it will be accelerated
that this
friction coefficient goes down about two
new play
and so now it is in exports
along the slope into plus expelled
action and so i can ride out now
newton's second law and they
which is
force and that's forcing the all the
defects election
would be equal and jean
finds a sign of pratap
minus
the frictional force now this becomes
u_k_
ports are clear
i'd lose my
and and saudi acceleration into positive
x direction that's the way i could find
positive exploration
equals
scientific data
minus
you okay
lines
to co-sign
that's acceleration in ulpan natural
question would be
was this big at which it reaches point b
well what we would have done early on in
the course
we would have said
rally by tony acceleration
and i know to distance and i know d
initial speeches zero
and clearly that distance alll
must be one-half
and square him being a part of a cake
incorporated b
and salty
would be
escreveu
of tooele
divided
what speed would have had been
the speed of d
eighteen
early all eight oh one
and so
that would be calm if we multiply this
by any
screw
a l
and if you want to see that in all
glories detail
then of course you have to take that
eight
and you have to multiplied it by two
allen st scrambled so we get to
g l
i'm signed or fade out
minus
you okay
practical climate data
and the whole thing
through the power
that is the speed
at point b
i however
would not to do it that way
i don't find it very elegant
i would say
why don't apply
it we're going to be figure
why don't say that the work done
ran that object moved from a to b
must be the connecticut energy
at point b
why does the connecticut edgy at point a
no i know that i'd really stupid zero
speed so this is europe
and so the kinetic energy had be is
clearly and one-half and
vbscript so it comes down now
to applying that we're going to do for
your own and calculating how much work
was done by all the forces at stake
conservative among conservative makes no
difference
and that political to one of them
vbscript
preferable when it goes from point a to
b
gravity
is doing
positive work
it's going down
and the amount of work that gravity is
doing
is plus an
g h
but age
divided by al
is the sign
buffet dot
so this is also a m g l
times this time
or data
all the paperwork
by gravity
so we have angie
i'm missile fayda
that ordered that contribution
by gravity and now we get the negative
contribution
why fiction
because the frictional forces
is uphill
but the motion is brought to heel
their hundred eighty degrees opposites
so i don't have to worry about the dots
product
the coastline of the angle
minus one
and so i can ignore
the dots and simply take that forced
frictional forces and multiplied by that
distant al but i have to move toward
state
sanmina sci
because the cosign
of that angle
equals minus one
and so i get
find the fictional force
which is u_k_
angie
cosine
fayda
that's the negative work done
friction
and is equals
quantcast and
vbscript
and i lose an m
and if you look very carefully
if you're willing to do that in your
head
you're going to talk to the left
you get to a g l
and then you get
digi signed greater
u_k_
co-sign kato before one how to get
exactly the same result
i find this
somehow more pleasing
use the
work energy field
so flexion does negative work
convert it into
but that's no problem for the work in a
jiffy lube
reno in life that friction
fixed kinetic energy out
whenever something is moving
it will come to the holes
if your spin at fault
that we know at the top
will not last very long
because of friction
and i have here
the pulp
i hope you can see it shortly there it
is
teeny weeny loophole very cute i play
with my office
and rotating
and you see that friction
is taking out connecticut reggie
and it's converting it to heat
he stay on the best milieu companies not
form on the floor
weakness great
so you see
that's what friction does fanatic energy
has been removed
and now
it has been converted to compete
if the third it is a little small so
then the desk
and so
i will give it a spin here
so it may last a little longer obviously
can't last very long
so very shortly
uh... it too will
pull over and come to rest
and that connecticut zero have been
concluded
into heat
all right so let's continue
now on another subject
and the one that i want to
talking about now is
i have a pendulum
at the time
at time t equals zero
is angle
is data zero
and i know that angle is
five degrees
which is approximately
ope warned or nine
radiance
at that time people zero
idealists
pendulum
tangential speed
i call it you'll be
because i call this point b
is going to park
i call this eight
the visit
circle
and it comes to a halt let's say here
at point c
and then this angle
is the maximum angle possible
state election
but the length of the pendulum for
simplicity simply be
in a small angle approximation
the angles will never be very large as
you will see you later when we calculate
data maximum
and so we know that we're going to get a
simple monocle so they should do it
very good approximation
source data
is going to be
angle theta maximum
funds because i or if you want to be my
guest
you can make this a sign
always work with both sides
omega p
crossfire
and omega
eclipses scrambled
of g_o_p_ al i will give you some
equations
during your exam but this one i will not
give you i_d_'s assume that you remember
this
and that the periods
of the pendulum
peoples to fight
i'm critical over g
so we know mehta
because we don't you know well
and now reasonable question is
what would be
maximum
in linux
waste
then we would know what they are maximum
because this part here
equals l
onto the coastline
corpsdata max
and so on this
ezell minus
elk or something
so it comes down to calculating
how high it is all jet comes about
twenty
outlaws at least into to heights
the swamp which i call eight swamp
and this one
which i call eight too
and so the one that we really want to
know
is what is a trunk was a pistol
because eight swamp
plus h two o
will be al times while mine is to
co-sign
data max
so remote web page won't let it still we
needed to have to be
maximum
it's one of the piece of cake
because we know
born to be dead this
object is at b
when kato zero is five degrees
so it's one
recalls l times while minors
cosine
of seen as a rock
you know state as they were
and so you'll find them if you were
interested in numbers but don't bother
if u
don't like numbers for the number that i
gave you disease or point oo
three eight meters it's only three point
eight milliliters
fifteen we need to know best large
displacement
in their direction with very little in
this direction
so we know ready what it wants to know
what it is
we could not
use the consultation
of mechanical energy
and we could say let us call arbitrarily
gravitational potential energy at point
it gets cold at zero
and going to apply the conservation of
mechanical energy which means
that the connecticut energy entity
lets the potential energy it
must be diplomatic energy had be
plus the potential energy had be
equals
the connecticut energy at sea
plus the potential energy at sea
not a potential energy of dated zero
because we define it that way
the kinetic energy had seen zero because
it comes to a halt
so now we can ride on that one haha
and
d_a_'s created
equals
not happen
vbscript
plus
angie
times age bomb
that has the potential energy at points
b
tired and disappointed eight
vertical separation h one
and that equals
the potential energy at point c
which is empty
times
each club
it still
and if you compare this part of the
equation
we see that you lose any g_-eight swamp
and so you find that
the squared
who carried it
the one-half of now we can still do that
equals and g
and so you will find
immediately eight still
it's true
equals
obese credit which is known
in our case it must be you know number
i'll give you meaningful than this
that is divided by two teens
and these two do you believe that i had
in mind
numbers are really not that important
you don't have a calculator anyhow
to expand
i was going to give this speed or point
three meters per second
in this direction
in order to keep the maximum angle
quite modest so i know it's true
and that i know it still
and i know it's one i can go to this
equation
and i can ask what is
the coast guard favor maxim
it's too by the way the case you're
interested in numbers
is about
opelika lol forty five
forty four point five millimeters
so it was originally
three point eight-millimeter zaid swamp
and no h two four point five mi would be
the fire
so you can calculate the cold finals
atomax
however
i said to myself if we use the
conservation of mechanical energy
can we know will also use
the work i think if you were
why not
that should work as well
the word out of this year and tells me
that the work done
on that object
when y'all get moved from a to b
equals a kinetic energy of the
minus the kinetic energy of eight
that is one huh
vbscript
by this won't happen
and
the eighth grade
and how much work was done by gravity in
going from a to b_ because credit is the
only force that does work
the tension is not doing any work
because the pension
which is in this direction
is always perpendicular
the direction of motion
work is a dot product between force
direction of motion
perpendicular to each other
footed zero
so it's only m_g_
that matters the gravitational force
loan and go straight to me
the work done by gravity is miners
engineer each one
of that goes up those negative work
people's minds and jim
now look at that
equation
and look
if you want to
compare that swamped
with this one
completely identical
photo we're going to do if you're in
is of course
in the wake of the famed as the
consultation
mechanical energy
the work done
many object goes from peter kenyon
is the kinetic energy of c
minus the kinetic energy
at dmg
that equals one house and
the c squid mine is gonna happen
discredit and that is the work
regretted is doing
when y'all get goes from b
lucy
that work is
minded and g h
so they see both minus and g
h
zero
and so you see what you see here
is exactly what you see shit
if you are identical
and so you could use the word energy if
you're in
allah or you can use the conservation of
mechanical energy that makes no
difference
and so you know can calculate their
maximum
and for those of you who won't some
numbers i've found that data maximum
wall sperm
well minus seven
point four degrees
noise get two angles
uh... ingredients that will be plus or
minus four point one three radians
you know because i know the end of this
error always get two angles
nothing you can do about it
and so now you can ask yourself the
question
what is fine five is always a bit of a
pain in the neck and it is really all
that much visited fi
but i was sort of curious
initial conditions walked by would be
and so that's
let's take a quick look at that
and so if we want to know if i use
we have to look at the initial condition
that
ating equals zero
velocity appointees close or point three
this direction
and we noticed a tight equals
data zero
and we know what data series that was
the five degrees at this point
or nine
radiance and so i'm going to substitute
that in my solution
so i know and people zero
i know dictator equal status zero
the fate of zero i know what they did
zero is
we just calculated what they don't maxis
articles time
applied akikko zero
and so i'll call
to angle so fine
plus and minus
you always find was an a-minus on
because the courts on the posting and
with the same cosine of my reasoning
so that we have to find on which of the
two a's
by the way
when you find
that they are maximum
equal split reminded all point won't
three iranians
you could have picking a plus or minus
arctic the plus
if you would pick the minus you were
found a different facing
but you can't pick minus
just want to remind you arctic plus
whatever follows
and so now i have to take into account
the
fact that at people zero
that i know the
velocity
vb
how did that come in well i think the
the remedy for that equation
marriage so i get that
buffet diabetes
which is the angular velocity radians
per second any moment in time but we're
going to value eight of the people zero
equals minus all made up
datamatics
under the sign
only dot t_
close by
real evaluated at people zero
one of the fatality
well do you think of the key is being
divided by l
this is the divided by help and is
therefore plus the whole point three
this process
at people zero d angle is increasing
so what is plus
how do we know will be over l
well remember we discussed that before
the kind of changes
the angle bynum aren't behavior
beneath these arc here i called it the
bs
leave the length is alll
and the definition of the fade out
evelyn williams is the as divided by l
if you divide both sides by g_t_e_ which
mathematicians kind of the woods
physicist can
you've got to the fate of the team
he called the actually
and that is the velocity divided by l so
you see that the state of the team he
departed bio
and so we don't have a second equation
reno
console fort sein fein
that give you again to angles
the give you an angle
fight through
and it gives you
hundred eighty degrees my despite two if
at the same value for sci fi
but only one of this
will be the same
as one of these
and that's the one that you pick
and in my case reform i tell you what
plus all point one three
i find them
equals minus open winds
to radians
it is about minus forty seven degrees
there's not much is it in the face and
what is interesting perhaps needs to
mention
that is we have children
the st
epstein people's you know if we have
given
speaking this direction all point three
leaders per second
if they are maximum would not have
changed of course not
but defy would have changed
in fact the five if you would have found
would be
plus all point eighty
and for those of you who have preferred
to use the fatal accident from fake
minus all point wong
they voted font
face angle altogether
all right i noticed this pope of course
must be death like to do a nail
let's just take a look at that
i can't believe
what's going on
your list and wife to rotating
ice friction locks
holy smoke
basic foundations of physics are at
stake again
and it seems that every time i'd
lectures we seem to have a way to
overthrow them
friction must
they connected eligio
i'm extremely puzzle
let's not look at it
i hate this what you think that i cannot
explain
biking them
let's just look look at it
let's go along with it would take a look
at the end of the lectures he was doing
but i gotta be dead right we can go on
forever
but let's not talk
this point
what i just did with the pendulum
i can do something
similar
with a spring similarly the census
peptide t_ equals zero
i stretched to spread a little and i
gave it to kick
and then i thought at all so late
very similar to
what i just think
but no
it is a
simpler problem
because of spring is exactly one that
meant you know addicted to relax lang
elvis spring
is his point eight
i stretch it to point b
i dated eight kick
i will not putting any numbers now undo
this speech vb
it comes to a whole year at point c
that the sprinkled syndicate
and we know we going to get today
for this is that people zero we're going
to get me
jumbo moment alteration exit polls x max
this is going to be
ex-lax
this is going to be
xvi
and his excavating
which is zero
so we're going to get back to my act
unto cosign
omega-three supply
same old story
getting or a
only got people to screw
ko plan and t equals to fight hard omega
ukrainians multi
on you're
what is now
x max
how would you approach it you've just
seen how i did it
with the
pendulum
adios first a conservation mechanical
and argue there was no friction
and then i showed you that it's
completely consistent with the work and
everything around
so what would you do not
how do we get x max
any suggestions any proposal
what they've done something from the
lapd
any idea to same concept
bernadine mitchell conditions
and we know it's a simple monocle
summation
and we want to know what the maximum
displacement is going to be
ideologue
first speak out the divorce case you're
wrong
lately i'm wrong so often before you
knew
thought through dot
so we try to cultivate a mechanic landed
anything wrong with that
many nothing wrong with it
but tried a consolation of a chemical
energy
the conservation of mechanical energy
tells me
the connecticut energy at eight
plus a potential an eternity
must be
because i think i think you could be
plus the potential energy had be
and that must be equal
because i think i know dat
the potential energy at sea
there's no friction down the long
conservative forces
so this go to work
well
for tential energetically
zero because remember
the potential energy over spring
is one-half k x quietly x's
the displacement
from israel exposition
so this is zero
when it comes to hold here
it is zero
when i watched his lecture i noticed
a slip of the time
clearly the potential energy at a zero
that's fine
but at sea
the object is standing still
so xy it is the connecticut activity
zero
and multiple pencil and that's it
and i continue to cook problem correctly
because i broke down here
one-half
x max
squid which is exactly the east room
that is the potential energy at sea
which reaches a maximum
is the kinetic energy that these iraqi
accidentally
mentioned at the polls potential image a
bit zero which is called the city
so we get that
one-half
dat
spread
equals one-half
vbscript
minus
export police clearance
that has the potential energy at this
location
and that equals
on top
axle see which we have called x max
script
uart in business
if i tell you radio object is with the
pan am i gave you the visual angle mike
data zero achille ready object is so you
know actual beat i'll tell you what's
been i dated so you know this one you
can calculate what the maximum statement
exactly the same idea and if you want to
applied we're going to be theorem of
course
you'll get executives result he act the
same thing
well that's not
true true
morton's
universal law
or bread
and believe it or not
i think i even give you on the exam
the gravitational force
of milken's universal law
that
i don't think you need it
you'll find it on the exam
that figure is going around the sun
uh... that's approximate nordic bite
so here is the worst
here's the sun
some and orbital
radius is
capital are
earth hasn't orbital
velocity
high-quality
orbital
they respond the object
immutable law students say
may have
goes around certain
velocity
and that has to be
you force on the system
gravitational force
which is the same as the
centrifugal force that's the only way
object can go wrong
in a circle
photograph additional forces
equals mass of the sun
about work
bungee
divided by our script
the force of gratitude
but also must be all league centrifugal
acceleration in this issue
amass group
and so it also is
muscle
on orbital speeds
that's great
provided by
orbital radius and if you prefer to
write that
in terms of only desperate
that's fine too
look at this year
you lose your
earth last if you want to know what you
were total speeders
it was one r
and so you find north must be equals
amassing some
buying
divided by heart
with the power
on top
and that is about
thirty kilometers per second
give it into a woman is the second but
of course
when you calculated make sure you always
stay in mt s before you make
conversion to other units
so you know the period is to go around
that is to buy art
divided by the orbital
and that is about three hundred sixteen
five-and-a-half days that's one year
follow it takes us to go
no i wondered what is the connecticut
energy
off the earth
in orbit
around
well that's completely trivial you would
say because
it is one-half
the mass of the earth
finds the orbital speeds graham
that is not
very difficult
sort of kinetic energy
all be worth in orbit
one-half
massive either
angie orbits
scratch
so i think there's a greater and i
screwed i lose the hot there
until i get
and so on
function
divided
that is the kinetic energy
in orbit
is off
atlantic city nj was
photograph here this is also
minus
one-half
potentially
and remember
the potential energy
equals minus
and so on
an earth
divided by our
so here you see plus hop
you she might as well
within haiti minus
haha the potential m
what is the total energy
of the earth
around to some that means the some
of potential energy
connecticut
the connecticut energy is minus mama
opulent
and a potential energies you
and so this is
cruises plus one hotlink
that means it's negative
because you were tel aviv negative
it is also equal to minus k
i'd just calculated for fun
how large that number is it's a negative
number i watch that is
and it turned out to be approximately
minus
two point seven
plunged into the thirty-three jokes
deeply negative
if we get bored and we want to
leave the solar system
then we can ask yourself the question
every month rocket duty earth and
require that rocket
how much speech should be given its to
get away from the song
once and for all and never come back
well all we would have to do
is make the total energy
of yours zero
so it controls all the way to infinity
and have zero speed when it gets there
how can i make a zero
well i have to adv
for the connecticut maji exactly k
because my newspapers case zero
if i have to adv
the kinetic energy katie then the new
connecticut energy
after the rock a broom
would be exactly to create a potential
and that is not changing
because you find a rock-ribbed when
you're there
and so you still at the same position
after all could fire and so you
potential energy hasn't changed
but you can add again if you must have
doubled
it'd have a double is doesn't become
zero
haha
it became energy bubbled
than the speed
must have gone up widespread would love
to
because kinetic energy is proportional
to the script
so you escape velocity
hegemony
this growth of two
find political philosophy
that would be forty earth the screw it
up to
i'm thirty which is about forty two
columbus
per second
by looking at the end of the
considerations
connection between
photo energy
schedule all city make the whole picture
internally
we talked a lot of a lecture
about logistics forces
i still remember the number of that
election was number twelve
because it's the one lecture but i
worked
wanted more than twenty other
with the help
my graduate student
day forty with it
he's wonderful
calculations medical solutions
and so
let's talk a little bit about
they resisted forces
in an object moved to a medium
hair or the cleats
there was a resisted forced
which always opposes the velocity
it has to terms
they want times eases the speeches is
always positive
must pay to
he spread
and this is the unit back there
of the velocity always opposing the
velocity
is the magnitude of the resistance force
we dealt exclusively was fierce remember
and we get some
george experiments which fears okay
while
equal so you want i'm sorry
and kato
equals
situ
are squid
and we did some experiments with
corn syrup
and it was the setup for weeks he won
was approximately one hundred sixty
and stick to
was about one point two
attempted to fill with cable grams per
cubic meters
avoiding them in the units of this
because that's always density
fact it's always a little smaller than
the actual dented the open
their crippled the chip itself
it is a more complicated
unit but you can figure that one out for
yourself
and so we had ballmer implementation of
an inch diameter three quarter of an
inch
and we drop them
karo syrup
if we take the one for now which is a
quarter openings diameter
and the mass of that one
is about four point one grams
renewed entity
of steel and so you can figure out
the master statement which we've
and so the question always
it is
ball bearing starts to fall what was the
speech that it will
g well
in the beginning
only and g
on that bull
and a teeny weeny little resisted force
as the
speed built up
he resisted force will grow
and comes a time
that it's equal
two m_g_ and then the object
will not the accelerated anymore an
adorable to recall
the pope terminal velocity
and so what i did conditions for
terminal velocity
this term equals and g
in other words that
c_-one
seemed to
art squid
this grant
becomes equal
two and g_ and when that's the case
then we have reached terminal
philosophy
there is this a m
quadratic equation in
view qty
you know if you want
you know see through you know to resolve
these ball bearing jynona maps of the
ball bearing
so we console for terminal
velocity you'll get to solutions it is
quadratic equation one that will be
known physical you will see
so you keep the wild
that these physical but if you get that
that would be
the city thing to do
and the reason why it would be serious
that i claim that this term
which by the way we called the press
charter
at this storm
and they completely ignored compared to
disturb
rich recall
viscous
how do we know that that pressure for
him
can be ignored
well that first
asked a question renders the fiske a
storm and the pressure for the same
for baltimore city
so forget from out of here at teens
would just want to know the disturb is
the same as this trip
that'll be the case
when the velocity
which we called the critical velocity
because he won't
divided by seemed to plans are
very easy to shell that this term
isn't exactly identical to that point
there's nothing critical about that
number
the wrong name critical velocity but we
do that that name
it simply means but the truth of the
people that all of means nothing else
if you calculate for quarter-inch
diameter steel ball bearing
you can calculate are
you will find that the critical velocity
is about a hundred miles crawler
and we know very well there is no way
when you drop a quarter a bull bearing
into this
sarah but it's going to come anywhere
near that so did speed will remain well
you know on that
miles per hour
and therefore
this is the term
that will dominate
and this term can be completely ignored
and a veteran candy norge
you conceded immediately terminal
velocity
is going to be and g
divided by c_-one our
and that by the way for our work
quarter-inch blow bearing
turns out to be something like two
centimeters per second
many many orders of magnitude lower
then the hundred miles per hour
which was a critical philosophy
what we did is we measured the times
for these ball bearings to full over a
distance of four sunny beaches
and if you know the time to go distance
of four centimeters
you know the terminal velocity
and we don't half of the ball bearing
we don't really out of the ball bearing
we don't see mom
no we didn't know steve on this i just
want to point out for you if you can
measure c_-one that way
your president speed
you know art you know m
you measure she wanted that's what i did
before going back to that morning
that's how i came up
with that number on the sixty otherwise
it wouldn't have known he was extremely
temperature-dependent if i could even
change between classes
temperature goes up
value forty one
goes down
so that's the way you can measure value
forty one
consultation of
momentum
we dealt with the conservation of
movement in one lecture you parents were
here
and we only dealt exclusively with
completely inelastic collisions
whenever
we have a system
objects
with zero net tax total force
the momentum must be conserved bacon
collide
they can
coal supply a workday can explore they
can break up into pieces
momentum
will be conserved
in the absence of any net external
it's a very non intuitive concept
connecticut energy can be destroyed
the momentum cannot be destroyed in the
absence of open that external forces on
the system as a whole
we have an object and love you
c_d_-rom
object and two
speed veto
let's make it very simple and one is one
kilogram abudrahm three meters per
second
and to two kilograms
detoured
equals
i think this might be just a second
i make these three weeks
momentum is conserved
so i can ride on that and long
ninety one
close and two
i've been to must be at marquis and
threw it is a completely thing about the
collision funds be prime they come
together they stick together the total
mass is going to be embalmed plus and
through and identified either in this
direction or in this direction but
whatever this i call it the prime
after the collision
you may say haiti you forgot you were
arrows here because this is a vector
equation
yeah i publicly forgotten because this
is the one the mental case you can
always leave the arrows all
because the science take care of it and
you course have to be generous namely
you have to go to my signs in
when needed
henry is one times five times plus five
and complete through is going to be
negative
because i must now observers as a minus
three so i get mine is six so
the momentum before and after the
commission must be minus one
and that must be equal to three times
the prime
anti-crime is therefore minus one third
of meters per second
and so these objects will stick after
the collision they will move
rhesus people one thirty
over needed per second
kinetic energy of almost exclusively
lost with almost nothing left remember
clearly that's because of friction not
external friction there is no external
fiction because if there were any
external friction
momentum will not be conserved
think of a method to car wrecks they're
going to each other
fireworks menu healed and scratch
manitoba metal
a lot of heat has produced kinetic
energy is removed
lengthen it's concert because builds
frictional forces all internal
and that's fine
that his wife to be so it's very mon
intuitive concept
that's now make sure
this crazy
object
has come to holtz
did not art
i'd better not say what i was going to
do
my goodness it still rotating
i realize that
it may cause a sleepless nights with all
the other hand written exam coming up
i would suggest you just forget about
this pretense you haven't seen it
protect this never happens
that may make you happier okay see you
monday and good luck
