recall concepts on
momentumand
momentum conservation;
define momentum and
collision;
identify what happens to
the momentum in the
event of a collision; and
1
At the end
of the
lesson, you
should be
able to:
2
3
3.
• Momentum (p)describes the motion of a body.
• All moving objects have momentum.
• It is actually obtained through the product of the body’s
mass and its velocity.
MOMENTUM
4.
where m isthe mass in kilogram (kg) and v is the velocity in
(m/s). Momentum has the same direction as the velocity. Its
unit is kg·m/s.
MOMENTUM
5.
From the figureat the right, we
can see that the velocity and
mass of a body affects its
momentum. Due to heavy mass,
it is difficult for the man to stop
the motion of the boulder. This
actually makes the boulder have
high momentum.
MOMENTUM
The momentum of the boulder and
man varies depending on
their mass and velocity.
6.
So for theman to not get
smashed, he needs to overcome
the momentum of the boulder by
increasing his velocity instead.
MOMENTUM
The momentum of the boulder and
man varies depending on
their mass and velocity.
7.
• If themomentum is steadily changing over time, then the
change in momentum per unit of time is equal to the net
force that is causing this change.
• This is actually in relation to the Newton’s second law of
motion.
MOMENTUM AND THE SECOND LAW OF MOTION
8.
where the subscriptsi and f indicates initial and final states of
the momentum and velocity, a is the acceleration in (m/s2
),
and Fnet is the net external force driving the change in
momentum.
MOMENTUM AND THE SECOND LAW OF MOTION
9.
MOMENTUM AND THESECOND LAW OF MOTION
The introduction of force during collision. This force changes the momentum of
bodies that collided.
10.
• During collision,force is exerted only during a very small
period of time.
• Thus, it is easier to analyze the collision in terms of
conservation of momentum, which states that: “In an
enclosed system, the total momentum before a collision is
equal to the momentum after a collision.”
CONSERVATION OF MOMENTUM
11.
The subscripts iand f denotes “initial” (before collision) and
“final” (after collision), respectively.
CONSERVATION OF MOMENTUM
12.
WHAT IS THEMOMENTUM OF A 0.165 KG HOCKEY
PUCK MOVING AT 20.0 M/S?
13.
Step 1: Identifywhat is required to find in the problem.
You are asked to calculate the momentum of the
hockey
puck.
Step 2: Identify the given in the problem.
The mass and velocity of the hockey puck are
given.
WHAT IS THE MOMENTUM OF A 0.165 KG HOCKEY
PUCK MOVING AT 20.0 M/S?
14.
Step 3: Writethe working equation.
Step 4: Substitute the given values.
Step 5: Find the answer.
WHAT IS THE MOMENTUM OF A 0.165 KG HOCKEY
PUCK MOVING AT 20.0 M/S?
15.
WHAT IS THEAMOUNT OF FORCE EXERTED ON A
TOY CAR IF IT HAS A CHANGE IN MOMENTUM
FROM 15 KG M/S TO 20 KG M/S FOR 5.0 SECONDS?
16.
Step 1: Identifywhat is required to find in the problem.
You are asked to calculate the net external force
acting on
a toy car.
Step 2: Identify the given in the problem.
The initial and final momentum, and the time
interval are
WHAT IS THE AMOUNT OF FORCE EXERTED ON A
TOY CAR IF IT HAS A CHANGE IN MOMENTUM
FROM 15 KG M/S TO 20 KG M/S FOR 5.0 SECONDS?
17.
Step 3: Writethe working equation.
Step 4: Substitute the given values.
WHAT IS THE MOMENTUM OF A 0.165 KG HOCKEY
PUCK MOVING AT 20.0 M/S?
18.
Momentum (p) isthe product of mass and velocity. It is
expressed as
Law of conservation of momentum states that in an
enclosed system, the total momentum before collision is
equal to the momentum after collision. This can be
expressed mathematically as
1
2
19.
1. What isthe momentum of a car of mass 75.0 kg travelling
at a velocity of 120 m/s?
2. Two bodies with initial momentum of 120 kg m/s and 150
kg m/s collides. After collision, the momentum of one body
is 135 kg m/s. What is the momentum of the other one?
SOLVE THE FOLLOWING PROBLEMS. SHOW YOUR
PERTINENT SOLUTION.
