NAPOLEON, I MEAN,
YOU'RE FIVE-NINE,
185 POUNDS.
I MEAN, YOU DON'T
HAVE THE MOMENTUM
OF SAY... SAY...
A DORSEY LEVENS.
HEY, MAN,
I GOT MOMENTUM.
NAPOLE, LISTEN.
IF IT WERE UP TO ME,
I WOULD SAY YES
BUT IT'S NOT ME,
IT'S THE BIG GUYS.
YOU KNOW, THE SUITS
AT THE NETWORK.
THEY'RE TELLING ME
I GOT TO DO A
SHOW ON MOMENTUM.
I GOT TO FIND
A RUNNING BACK
WITH MOMENTUM.
I GOT MOMENTUM.
 SPORTS FIGURES--
 PUTOUR BRAIN IN THE GAME.
■
( sighs )
USUALLY WHEN WE THINK
ABOUT COLLISIONS
WE TNK ABOUT CARS, RIGHT?
( grunts )
BUT, OBVIOUSLY, COLLISIONS ARE
BIG PART OF FOOTBALL, TOO.
( grunting )
COLLISIONS ARE ALSO
A BIG PART OF SCIENCE.
IN PHYSICS, WHENEVER
TWO OBJECTS COME TOGETHER
WE HAVE WHAT SCIENTISTS CALL...
...A COLLISION.
NOW, COLLISIONS CAN BE BIG...
...OR SMALL.
BUT ENEVER TWO OBJECTS
COME TOGETHER
WE HAVE A COLLISION
AND YOU CAN'T HAVE A COLLISION
WITHOUT MOMENTUM.
SI IS PRETTY IMPORTANT
IN FOOTBALL, RIG?
LIKE, IF I WEIGHED 500 POUNDS
I COULD PROBABLY
MOVEHIS THING PRETTY EASILY
BECAUSE I'D HAVE A LOT
MORE WEIGHT TO THROW AT IT.
WE SEE THIS IN FOOTBALL
ALL THE TIME.
THAT MES SENSE, RIGHT?
SOMETHING HEAVIER SMASHES
INTO SOMETHING LIGHTER
AND THE LIGHTER OBJECT MOVES.
THAT'S BECAUSE THE HEAVIER
OBJECT HAS MORE MOMENTUM.
SO, UH...
HOW DO YOU EXPLAIN THIS?
 NAPOLEON
 ONLY WEIGHS 185 POUNDS.
 THE DEFENDER WEIGHS 31POUNDS.
 WHEN THE TWO OF THEM COLLIDE,
 HOW COULD NAPOLEON EVER SCORE?
( gasping and grunting )
HOW COULD A SMALLER PLAYER
HAVENOUGH MOMENTUM
TO PH BACK A GIANT DEFENDER,
AND SCORE?
THIS GUY BACK BEHIND M
IS A PRETTY HEAVY-DUTY OBJECT.
HIS NA IS NAPOLEON KAUFMAN
AND HE'S A RUNNING BACK
FOR THE OAKLAND RAIDERS.
LAST YEAR, HE BROKE
BO JACKSON'S TEAM RECORD
FOR YARDS IN A GAME
WITH27 YARDS ON 28 CARRIES.
 FIVE-FOOT-NINE, 185 POUNDS
HE'S ON THE SMALLER SIDE
FOR AN NFL BACK
SO HOW DOES HE TAKE THE POUNDING
FROMLL THOSE DEFENDERS?
WHAT ARE SOME OF THE ADVANTAGES
AND DISADVANTAGES
TO BEING A SMALLER BACK
IN THE NFL?
WELL, I'D SAY AN ADVANTAGE
IS TT, YOU KNOW, SOMETIMES
CONSIDERING HOW BIG
THE LINEMEN ARE IN THIS LEAGUE
YOU KNOW, WE
CAN KIND OF
HIDE BEHIND THE BIG GUYS,
YOU KNOW.
AND ANOTHER THING
 THE SPEED FACTOR, YOU KNOW.
A LOT OF THE LINEBACKERS,
THEY'RE ST...
NOW, THERE ARE SOME
THAT ARE FAST
BUT THEY'RE NOT ASAST
AS SOME OF US
SO IT DEFINITELY PLAYS
TO OUR ADVANTAGE.
I GUESS YOU NEVER GET CAUGHT,
RIGHT?
YOU JUST BLAZE PAST
THESE DEFENDERS ALL THE TIME?
OH, NO. AT'S DEFINITELY
NOT THE CASE, YOU KNOW.
OBVIOUSLY, LINING UP MOST OF
THE TIME SIX, SEVEN YAS DEEP
YOU HAVE TO, YOU KNOW,
GENERATE ENOUGH MOMENTUM
TO PLOW INTO THESE GUYS
AND BREAK TACKLES.
AND,OU KNOW,
A LOT OF THE SMALL BACKS
ARE REALLY DOING THAT LATELY
BECAUSE OF THE SPEED FACTOR
AND BECAUSE OF THE FACT THAT,
YOU KNOW
WE GET A CHANCE TO-TO GET
A HEAD START ON THE GUYS.
RIGHT, AND GET
SOME STEAM GOING?
YEAH.
( cheering )
MOMENTUM IS AROUND US
ALL DAY, EVERY DAY.
NOW, IF WE HAVE
MORE THAN ONE MOMENTUM
WE CALL IT "MOMENTA.
THAT'S PLURAL FOR "MOMENTUM."
WHOA!
( thud )
( grunts )
NOW I DON'T.
YOU SEE, MOMENTUM IS
SORT OF LIKE, UH...
THE QUANTITY OF MOTION.
AND PART OF IT IS HOW MUCH
AN OBJECT WANTS TO KEEP MOVING.
AND THE MORE MOMENTUM YOU HAVE,
THE HARDER IT IS TO STOP
AND THE MORE IT HURTS...
WHEN SOMETHING STOPS YOU.
( grunting )
A LITTLE MOMENTUM D...
( grunts )
...A LOT OF MOMENTUM
THE QUANTITY OF MOTION--
MOMENTUM.
WHEN SOMETHING BIG AND HEAVY
IS COMING RIGHT AT US
WE KNOW INSTINCTIVELY THAT
IT'S GOT A LOT OF MOMENTUM
AND WE KNOW
TO GET OUT OF THE WAY!
( trumpeting )
THAT'S WHY MOST FOOTBALL PLAYERS
ARE SO BIG.
THEIR BIGGER SIZE
GIVES THEM GREATER MOMENTUM
WHEN THEY'RE MOVING.
WHAT IF I TOLD YOU
THAT THIS BOWLING BALL
AND THIS SOCCER BALL
COULD HAVE THE SAME MOMENTUM?
NO WAY.
( uckles )
WAY, MARQUEZ.
I'LL SHOW U.
HOW WAS THAT?
NOT REAL HARD.
IT WAS GOING SO SLOW THAT
 DIDN'T HAVE MUCH MOMENTUM.
OKAY, I'M GOING TO TRY
THE SOCCER BALL, ALL RHT?
HOW WAS THAT?
ABOUT THE SAME
AS THE BOWLING BALL.
OKAY,
THEY HAD THE SAME MOMENTUM
SO WHAT DOES THAT TELL US?
IT WAS GOING FASTER
SO MOMENTUM DEPENDS
ON BOTH SPEED AND MASS?
CORRECT. IN AN EQUATION,
IT LOOKS LIKE THIS:
 "P" (MENTUM) EQUALS MASS
 TIMES VELOCITY.
 SO THE AMOUNT OF MOMENTUM
 AN OBJECT HAS
 IS A FUNCTION OF BOTH
 ITS WEIGHT-- ITS MASS--
 AND ITS SPEED-- ITS VELOCITY.
OH, THIS IS WHAT MOMENTUM
LOOKS LIKE IN AN EQUATION--
A LOWERCASE "P."
NOW, WHY A "P"?
I HAVE NO IDEA.
YOU JUST GOT TO MEMORIZE THAT.
"P" EQUALS MOMENTUM.
"P" EQUALS MOMENTUM.
P = MV, OR...
MV = P.
MVP-- GET IT?
NOW I HAVE MOMENTUM.
I HAVE MASS, AND I HAVE VELOCITY
SO I MUST HAVE MOMENTUM.
AND WE CAN FIGURE OUT
MY MOMENTUM REALLY EASILY.
WE JUST HAVE TO MULTIPLY
MASS BY VELOCITY.
NOW HERE'S SOMETHING REALLY SICK
ABOUT MOMENTUM.
IF THERE'S NO OUTSIDE FORCE
TO CHANGE IT
THE MOMENTUM STA THE SAME.
MOMENTUM JUST KEEPS
GOING AND GOING... FOREVER.
THAT'S CALLED
THE CONSERVATION OF MOMENTUM
AND IN PHYCS, THAT'S A LAW.
MOMENTUM MUST BE CONSERVED.
NOW I DON'T HAVE MOMENTUM.
I'M STOPPED.
WELL, WHAT HAPPENED?
AN OUTSIDE FORCE
AFFECTED MY MOMENTUM.
IN THIS CASE, IT WAS
THE FRICTION OF MY WHEELS.
FRICTION IS A FORCE
THAT AFFECTS MOMENTUM.
BECAUSE MOMENTUM IS CONSERVED
IT CAN BE PASSED
FROM ONE OBJECT TO ANOTHER.
THE MOMENTUM IS PASSED
FROM ONE BALL TO THE NEXT.
NOW, WITH NO OUTSIDE FORCE
TO AFFECT IT
THE MOMENTUM CAN GO ON...
FOREVER.
 WHEN A PLAYER IN MOTION
 HITS A STATIARY PLAYER
 AND THEY STICK TOGETHER
 LIKE THIS
 THEY BECOME ONE OBCT.
 THAT'S CALLED
 A STICKY COLLISION.
 THE MOMENTUM STA THE SAME
 BUT NOW THEY HAVE
 A GREATER MASS
 BECAE THERE ARE TWO OF THEM.
BUT IT SEEMS LIKE YOUR MOMENTUM
IS LESS AFTER YOU MAKE CONTACT.
ACTUALLY, NAPOLEON,
IT'S YOUR SPEED THAT'S LESS.
YOUR MOMENTUM STAYS THE SAME.
NOW WE CAN FIGURE IT OUT
WITH JUST A LITTLE MATH.
WE'RE GOING TO MULTIPLY
KILOS BY METERS PER SECOND.
FOOTBALL IS POUNDS AND YAR.
FORGET ALL THAT METRIC STUFF.
YEAH, BUT YOU SEE,
IF WE USE POUNDS
WE HAVE TO FIGURE IT OUT
WITH SLUGS.
SLUGS?!
YOU DON'T WANT TO KNOW.
YEAH, LET'S JUST STICK
WITH THE METRICS.
 WE CAN FIND A NUMBER
 FOR THE DEFENDER'S MOMENTUM
 BEFORE HE MAKES E TACKLE
 AND AFTER HE MAKES CONTACT.
 WE KNOW E DEFENDER'S WEIGHT:
 290 POUNDS OR APPROXIMATELY
 130 KILOGRAMS.
 TO FIND HIS VELOCITY
 WE'LL USE THE VIDEO FRAMES.
 EACH FRAME
 IS 1/30th OF A SECOND.
 THE DEFENDER IS MOVING A FOOT
 FOR EVERY 30th OF A SECOND
 SO, 30 FEET A SECOND
 OR NINE METERS PER SECOND.
 SO WE HAVE MASS AND VELOCITY.
 MULTIPLY AND WE GEMOMENTUM.
 1,170 KILOGRAMS-METERS
 PER SECOND.
 NOW LOOK WHAT HAPPENS
 AFTER TH MAKE CONTACT.
 BECAUSE THEY STICK TOGETHER
 THEY'RE NOW MOVING
 AS A SINE MASS.
 WE ADD THE DEFENDER'S MASS
 AND THE RUNNING BACK'S MS
 TO GET A NEW MASS OF 214 KILOS.
 THAT'S 471 POUNDS.
 WE FIGURED OUT THEIR VELOCY:
 5.467 METERS PER SECOND.
 SO IF WE MULTIPLY OUR NEW MASS
 BYUR NEW VELOCITY
 WE GET 1,170 KILOGRAMS-METER
 PER SECOND.
 THE SAME MOMENTUM
 WE HAD BEFORE.
( grunting )
THE MOMENTUM
IS CONSERVED.
 THE MOMENTUM
 BEFORE A COLLISION
 IS THE SAME
 AFTER A COLLISION.
THAT WOULD ONLY WO
IF THE QUARTERBACK
HAD NO FRICTIONAL FORCE
AGAINST THE GROUND.
GHT. BUT FOR
THAT MODEL WE'LL
SAY HE DN'T.
IF HE DID, THE
MOMENTUM WOULD
BE REDUCED
BY THE AMOUNT
OF FRICTION.
BUT BECAUSE THERE'S
NO OUTSIDE FORCE
THE MOMENTUM
STAYS THE SAME.
ON A FOOTBALL FIELD
'S USUALLY BOTH PLAYERS
WHO ARE MOVING, RIGHT?
WELL, LET'S SAY
WE HAD TWO PLAYERS
WITH THE SAME MASS
AND THEY HIT EACH OTR
WITH EXACTLY THE SAME VELOCITY
IN OPPOSING DIRECTIONS.
WHAT WOULD HAPPEN?
LET'S GO TO THE SPORTS FIGURES
BLACKBOARD AND TAKE A LOOK.
ANY TIME A DEFENSIVE LINEMAN
AND AN OFFENSIVE LINEMAN
GO HEAD-TO-HEAD
YOU HAVE A COLLISI
OF MAJOR LEAGUE PROPORTION.
WEIGHING IN THE NEIGHBORHOOD
OF 3 POUNDS EACH
THESE PLAYERS CARRY
A LOT OF MOMENTUM.
SOHAT HAPPENS WHEN THEY MEET?
 THEY BOTH GET OFF THE LINE
 EQUALLY WELL
  THEIR VELOCITY IS THE SAME
 WHEN THEY MEET.
 THE OFFENSIVE LINEMAN
 HAS MOMENTUM IN THIS DIRECTION.
 WE'LL CALL THAT POSITIVE.
 AND THE DEFENSIVE LINEMAN
 HAS MOMENTUM IN THIS DIRECTION.
 WE'LL CALL THAT NEGATIVE.
 WHEN TWO OBJECTS COLLIDE
 WE CAN TAKE THE SUM
 OF THEIR MOMENTUM
 TO FIGURE OUT
 WHAT'S GOING TO HAPPEN.
 WHEN THEY HIT HEAD-ON
 WE ADD THEIR TWO MOMENTA
 TO GET ZERO.
 THEY STOP.
 TWO BIG PLAYERS,
 ONE BIG COLLISION.
YOU D THEM UP,
YOU GET ONE BIG ZERO.
THEIR EQUAL AND OPPOSING MOMENTA
CANCEL EACH OTHER OUT.
IT'S ALL IN THE NUMBERS.
I'M MARK MALONE AT THE
 ORTS FIGURES BLACKBOARD.
( all grunting )
ALL THAT STUFF WORKS WHEN
YOU HIT EACH OTHER HEAON.
BUT MOST OF THE TIME
IT'S NOT THAT WAY.
WE HIT EACH OTHER AT ANGLES.
RIGHT, BUT THE MOMENTUM
IS STILL CONSERVED.
SO NAPOLEON, WHAT HAPPENS
WHENOU'RE RUNNING
AND A DEFENDER
HITS YOU AT AN ANGLE?
WELL, USUALLY WE KEEP MOVING
BUT IN A DIFFERENT DIRECTION.
THAT DIRECTION IS THE SUM
OF YOUR TWO MOMENTUM
YOURS AND THE DEFENDERS.
 NAPOLEON HAS MOMENTUM
 ANHE GETS HIT
 AT A 90 DEGREE ANGLE
 BY A DEFENDER.
OKAY, SO WHADO
WE GOT HERE?
NAPOLEON HAD A MOMENTUM
IN THIS DIRECTION.
UH-HUH.
THE DEFENSIVE BACK
HAD MOMENTUM
IN THIS DICTION.
WHEN THEY COLLIDED,
THEY WENT OFF INTO
THIS DIRECTION.
( grunting )
RIGHT. NOW BECAUSE
THEY HIT AT AN ANGLE
 CAN'T SIMPLY
ADD ONE MOMENTUM TO THE OTR
LIKE WE DID
WHEN THEY HIT HEAD-ON.
NOW TO FURE OUT MOMENTUM
IN DIFFERENT DIMENSIONS
WE USE ARROWS LIKE THIS.
THEY'RE CALLED "FORCE VECTORS."
( crashing sound )
OKAY, THIS ARROW HERE
REPRESENTS THE SUM
OF OUR TWO MOMENTA.
AT'S OUR TWO MOMENTA
ADDED TOGETHER.
KONG, WHAT IF NAPOLEON
AND THE DEFENDER
HAD EXACTLY THE SAME MOMENTUM?
THEY WOULD'VE GONE
INHIS DIRECTION.
RIGHT, BUT THEY DIDN'T.
SO WHAT CAN WE TELL
ABOUT THEIR MOMENT
FROM OUR VECTORS?
NAPOLEON HAD
A GREATER MOMENTUM
CAUSE THEY WENT
MORE IN THE DIRECTION
HIS MOMENTUM WAS GOING IN.
CORRECT.
NOW, YOU CAN USE VECTORS
LIKE THIS
TO FIGURE OUT ACTLY
WHAT THE RELATIVE MOMENTUM
FOR DIFFERENT OBJECTS WERE
 BEFORE A COLLISION.
THAT'S WHAT THIS GENTLEMAN
DOES FOR A LIVING.
THIS IS STEVE LOVELL
AND HE'S A TRAFFIC
INVESTIGATOR
FOR THE OAKLAND
POLICE DEPARTMENT.
SO, STEVE, HOW DO YOU
USE PHYSICS IN POLICE WORK?
I RECENTLY INVESTIGATED
THIS ACCIDENT.
IT WAS COMING OFF
A RESIDENTIAL ROWAY.
THE DRIVER SAID
THAT HE STOPPED
AT THE STOP SIGN
PROCEEDEINTO
THE INTERSECTION
AND THEN STRUCK
THIS CAR ON THE SIDE.
WELL, BAD ON THE
WEIGHT OF THE CAR
THE WEIGHT
OF THIS VEHICLE
THE ANGLES OF APPROACH
AND ANGLES OF DEPARTURE
USING MOMENTUM I CAN
ACTUALLY CALCULATE
THE DRIVER'S SPEED
TO FIND THAT HE'S
NOT ALL TRUTHFUL
WHEN SAYING HE STOPPED
AT THAT STOP SIGN.
AT THE STOP SIGN.
( metal crunching )
NOW, NAPOLEON, YOU WEIGH...
OUT 185 POUNDS.
OKAY, SO THAT WOULD BE
83 KILOS.
SO WE'RE GOING TO INCREASE
YOUR MOMENTUM WITH..
VELOCITY.
RIGHT.
 NAPOLEON HITS
 THE LINE OF SCMMAGE
 AT 3.66 METERS PER SECOND.
 83 KILOS TIMES
 3.66 METERS PER COND
 IS 3.8 KILOS-METERS
 PER SECOND.
 THAT'S A LOT OF MENTUM.
■
AND BEUSE I WEIGH LESS,
I CAN GET UP TO SPEED FASTER
BECAUSE MY INERTIA IS LESS.
INERTIA?! WELL, WELL.
NAPOLEON YOU'VE BEEN STUDYING
A LITTLE PHYSICS, VEN'T YOU?
OH, A LITTLE.
( crowd cheering )
SO, WHAT HAVE WE LEARNED?
THAT MOMENTUM IS LIKE
A QUANTITY OF MOTION.
RIGHT.
AND THAT WE CAN FIND
THE NUMBER FOR MOMENTUM
BY MULTIPLYING THE OBJECT'S MASS
BY ITS VELOCITY.
CORRECT.
AND THAT MOMENTUM IS CONSERVED--
THE LAW OF CONSERVATION
OF MOMENTUM.
RIGHT... THAT'S GHT.
THAT'S RIGHT.
THAT MEANS THAT MOMENTUM
WILL CONTINUE
TIL ACTED UPON
BY SOME OUTSIDE FORCE.
OKAY. AND THEN...
AND IN A COLLISION,
WE CAN ADD THE TWO MOMENTA.
OKAY. ALL RIGHT, THAT WAS GREAT.
( groans )
WELL, I'D LIKE TO THANK
NAPOLEON KFMAN
AND THE OAKLAND RAIDERS.
I GOT MOMENTUM.
( grunting )
AND, OF COURSE, OUR STUDENTS:
 MARQUEZ, MOHAMMED...
 VERONICA, ASHA AND KONG.
 OFFICER STEVE LOVELL
 OF THE OAKLAND
 POLICEEPARTMENT
FOR HELPING US OUT TODAY
ON ESPN'S SPORTS FIGURES:
"RUNNING WITH MOMENTUM."
