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1. 1
My bio referensiLatihanMateri

2. 2
my bio referensiLatihanMateri
Materi 1
Materi 2
Materi 3

3. 1. NAMA:SANTY MEILISA
MANURUNG
2. NIM:RSA1C314005
3. PEND.FISIKA PGMIPA-U
3

4. Momentum is conserved!
The Law of Conservation of Momentum: “In the absence of an
external force (gravity, friction), the total momentum before
the collision is equal to the total momentum after the
collision.”
smkgp
smkgp
smkgp
smkgp
smkgp
smkgmvp
total
car
truck
totalo
caro
otrucko
/*3300
/*18005.4*400
/*15003*500
/*3300
/*800)2)(400(
/*2500)5)(500(
)(
)(
)(







5. A “no stick” type collision
Spbefore = Spafter




1
1
1
22112211
100010000
)10)(3000())(1000(0)20)(1000(
v
v
v
vmvmvmvm oo
-10 m/s

6. BackwardsInelastic-Explosions
Suppose we have a 4-kg rifle
loaded with a 0.010 kg bullet.
When the rifle is fired the
bullet exits the barrel with a
velocity of 300 m/s. How fast
does the gun RECOIL
backwards?
Spbefore = Spafter




2
2
2
2211
430
))(4()300)(010.0()0)(010.4(
v
v
v
vmvmvm TT
-0.75 m/s

7. Example Granny (m=80 kg) whizzes
around the rink with a velocity
of 6 m/s. She suddenly collides
with Ambrose (m=40 kg) who
is at rest directly in her path.
Rather than knock him over,
she picks him up and
continues in motion without
"braking." Determine the
velocity of Granny and
Ambrose.How many objects do I have before the collision?
How many objects do I have after the collision?
2
1



 
T
T
TToo
ab
v
v
vmvmvm
pp
120)0)(40()6)(80(
2211
4 m/s

8.  .
8
Referensi
s

9. Honors Physics

10. 
Impulse – Momentum Relationships

11. 
Impulse – Momentum Theorem
vmFt 
IMPULSE CHANGE IN MOMENTUM
This theorem reveals some
interesting relationships such
as the INVERSE relationship
between FORCE and TIME
t
vm
F



12. 
Impulse = Momentum
Consider Newton’s 2nd Law and
the definition of acceleration
Units of Impulse:
Units of Momentum:
Momentum is defined as “Inertia in Motion”
Ns
Kg x m/s

13. 
Impulse – Momentum Relationships
VmfT 
Constant
Since TIME is directly related to the
VELOCITY when the force and mass are
constant, the LONGER the cannonball is
in the barrel the greater the velocity.
Also, you could say that the force acts
over a larger displacement, thus there is
more WORK. The work done on the
cannonball turns into kinetic energy.

14. 
How about a collision?
Consider 2 objects speeding
toward each other. When they
collide......
Due to Newton’s 3rd Law the
FORCE they exert on each other
are EQUAL and OPPOSITE.
The TIMES of impact are also
equal.
Therefore, the IMPULSES of the 2
objects colliding are also
EQUAL
21
21
2121
)()(
JJ
FtFt
ttFF




15. 
How about a collision?
If the Impulses are equal
then the MOMENTUMS
are also equal!
22221111
222111
2211
21
21
)()(
oo
oo
vmvmvmvm
vvmvvm
vmvm
pp
JJ





22112211 vmvmvmvm
pp
oo
afterbefore

 

16. 
Types of Collisions
A situation where the objects DO NOT STICK is one
type of collision
Notice that in EACH case, you have TWO objects BEFORE and AFTER
the collision.

17. 
The “explosion” type
This type is often referred to as
“backwards inelastic”. Notice you
have ONE object ( we treat this as a
SYSTEM) before the explosion and
TWO objects after the explosion.

18. 
Collision Summary
Sometimes objects stick together or blow apart. In this
case, momentum is ALWAYS conserved.
2211)(
022011
2211022011
vmvmvm
vmvmvm
vmvmvmvm
pp
totalototal
totaltotal
afterbefore



 
When 2 objects collide and DON’T stick
When 2 objects collide and stick together
When 1 object breaks into 2 objects
Elastic Collision = Kinetic Energy is Conserved
Inelastic Collision = Kinetic Energy is NOT Conserved

19. 
Elastic Collision
JAfterKE
JAfterKE
JmvBeforeKE
car
truck
car
000,50)10)(1000(5.0)(
000,150)10)(3000(5.0)(
000,200)20)(1000(5.0
2
1)(
2
2
22



Since KINETIC ENERGY is conserved during the collision we call this an
ELASTIC COLLISION.