impuls and momentum

1. Basic Competencies
Learning Activities
indicator
Guide
Krisna Suryanti
RSA1C314011
Assessment
Exercise

2.  What is it ??

3. Momentum
Momentum is:
the tendency of a moving
object to continue moving at
a constant speed,
or the multiplication of
mass with velocity object.
formulated:
P = m.v
By: p = momentum (kg m /
s)
m = mass of the object (kg)
v = velocity (m / s)

4. Basic Competencies
 shows the relationship between the concept of
impulse and momentum to solve the problem of
collisions

5. LEARNING ACTIVITIES
 • Discuss the concept of momentum, impulse, the
relationship between impulse and momentum in class
discussions
• Experimenting law of conservation of momentum
• Analyze the impact problem solving by using the law of
conservation of momentum

6. indicator
 • Formulating the concept of impulse and momentum, the
relationship between them, and their application in life (eg
rocket)
• Formulate the law of conservation of momentum for a
system without external forces
• Integrating the law of conservation of energy and
momentum conservation for many collision events

7.  Assessment of performance (attitudes and
practices), the written test
Assessment

8. Guide
 Physics books relevant
Materials: worksheets, student reports, presentation
materials
Tools: dynamic wagon, sled, tiker timers, media
presentations

9. Exercise

10. THE LAW OF CONSERVATION OF
MOMENTUM
 Two balls each having a mass m1 and m2, where m1 = m2.
m1 m2 moving towards the stationary (v2 = 0). After the
collision velocity turned into v1 'and v2'. When F12 is the
style of m1 m2 used for mashing and F21 style of m2 used
for mashing m1, then according to Newton's Third Law:

11.  Total momentum of the object 1 and object 2 before
and after the collision is equal / fixed. This law is
called the Law of Conservation of Momentum.

12. What impulses relationship with Momentum?
 One of Newton's law says that the force acting on an object is equal
to the mass multiplication with the acceleration.
F = m.a.
If we enter into the formula I = F Δt
I = F. Δt
I = m.a (t2-t1)
I = m v / t (t2-t1)
I = m.v1 - mv2
 "the magnitude of the impulse that works / worked on an object is
equal to the change in the momentum of the object."

13. IMPULS
 Impulse is defined as:
the product of the force by the time required by the
force to moving .Impuls can be formulated:
I = F. ∆ t
By: I = impulse
F = force (N)
Δt = time interval (s)

14.  According to Newton's 2nd law:
F = m a
By substituting the second equation is obtained
I = F Δt = mvt – mv0
with:
MVt = momentum of the object, as the speed vt
MV0 = mementum object when the velocity v0

15. Impulse as momentum changes
The concept of impulse and momentum changes can be viewed as
a concept that arises from the application of Newton's second law
, namely : (1.3)F ma
m
Play
Analisis Animasi
m
F v1
m
v
2
Animation : Stick provides a
force ( F ) on the ball of mass ( m
) , then the ball velocity changes
( v = v1 - v2 ) in the interval (
t ) .
A change of pace on the object will give the average acceleration
of :
2 1
(1.4)
v v
a
t



The substitution of equation ( 1.4 ) to equation ( 1.3 ) , obtained
 
2 1
2 1 (1.5)
v v
F m
t
F t m v v
 
  
 
  
Magnitude F t called impulse , which means that the impulse is the change
in momentum.
!
Animasi

16. EXAMPLE
The working principle is the main
rocket conservation of momentum .
The number of rockets on the runway
momentum equal to zero . When a
rocket is launched , has sprayed
down the burning of a high-speed jets
of gas is made ​​rocket moves
upwards to compensate for the gas
momentum .
The law of conservation of momentum on
the rocket , namely :
Play
INDONESIA
Animasi 9:
( ) ( )
(1.15)R
mv m
F v
t t
 
 
 
desain: bugishq blog
1 1 2 2
1 1 2 2
0 ' '
' ' (1.14)
m v m v
m v m v
 

Impulse is the change in momentum
(F t = p= (mv)):
So, force rockets is :

17. Collision
 The collision was an event meets two moving objects.
When the collision apply the law of conservation of
momentum but not always apply the law of
conservation of kinetic energy. Maybe some kinetic
energy is converted into thermal energy due to the
collision.

18. Collision
A collision occurs when a moving object on another
object that is stationary or moving too . For example
, a billiard ball collision or collision between two cars
on the highway .
A B
Play
desain:bugishq blog
Animasi 4
The collision that occurs when the mass center point of the
object toward the center of mass of the object point to another .
As shown in the following animation .
amount of mechanical energy of the system ( objects that collide ) is
not always fixed , likely after the collision energy turns into heat .
However , the amount of momentum of the system is always fixed .

19. Perfectly elastic collision
Perfectly elastic collision is a
collision between two objects
remain the same amount of
mechanical energy is great, just
before and after the collision .
In other words , perfectly elastic
collision no energy is lost
Thus , the elastic perfectly valid : law
of conservation of momentum law of
conservation of mechanical energy
For example , two balls with the
respective masses mA and mB ,
initially moving with velocity v1 and
v2 . after the collision , the speed of
the ball becomes v1 ' and v2 ' . Note
animations
desain: bugishq blog
v1 v2
►Bola sebelum tumbukan
Play
►Bola saat tumbukan
v2’v1’
►Bola sesudah tumbukan
►Perhatikan animasinya
Animasi 5

20. collision resilient portion

In the collision elastic portion only applies
the Law of Conservation Momentum ,
while the Energy Conservation Law does
not apply , because the kinetic energy after
the collision smaller objects before the
collision . It is caused when there is no
collision energy into heat or sound energy .
1. Apply the law of conservation of
momentum ' '
1 1 2 2 1 1 2 2m v m v m v m v  
Feature collision resilient portion :
2. Do not apply the law of conservation of
mechanical energy
3. The coefficient of restitution ( e ) valued at
between zero and one : 0 1e 
desain: bugishq blog
lantai
Play
Animasi :

21. RESILLIENCE NOT AT ALL
 Elastic collision not at all characterized by:
 1.Applicable law of conservation of momentum.
 2.Not applicable law of conservation of kinetic
energy.
 3.Restitution coefficient of zero

22. The collision between two
objects with no resilience at all ,
then after the collision of the two
bodies will have the same speed (
v'1 = v'2 = v ' ) , because the
coefficient of restitution equal to
zero ( e = 0 ) Note animation 8 !
' '
1 1 2 2 1 1 2 2m v m v m v m v  
In general, the impact resilience is not at all apply the law of conservation
of momentum
Because the speed of the two objects after the collision the same ,
namely :
Then the law of conservation of momentum equation ,
becomes :
desain: bugishq blog
Play
Animasi :
1 2
v11 2v2
v'1 =v’2 =v’
' ' '
1 2 (1.12)v v v 
  '
1 1 2 2 1 2 (1.13)m v m v m m v  