The area between a graph of Force line and the
horizontal axis of Position gives work done.
The area between a graph of Force line and the horizontal
axis of Time gives the impluse delivered to an object
The unit of Impulse is Newton*seconds
The unit of momentum is kg* m/s
Important Concepts
Why is "momentum" important ?
Newton
wrote his Second Law of Forces as FDt
= m Dv
not as
F = ma. By doing so, he connected
force to the
length of time
the force is delivered as the cause of motion.
The result in motion is the product
of mass and the change
in velocity.
Simply
stated, FDt
(termed "impulse")
is the cause of motion!
m
Dv ( the change in momentum) is the
result of impulse.
ALL MOTION IS CONNECTED
TO IMPULSE AND MOMENTUM!
Info
Box #2
Momentum is a vector.
As a vector, each component must follow the Conservation
of Momentum Law.
The
Law of Conservation of Momentum
can be stated to emphasize the vector
nature of momentum .
The sum of the x components
before equals the sum of the x components after collision.
The sum of the y components
before equals the sum of the y components after collision.
1.
Totally
elastic-- both momentum and kinetic energy are conserved
2.
Partially elastic-- momentum is conserved but some kinetic
energy is lost is some deformation of shape during the
collision.
3.
Totally inelastic-- momentum is conserved but a great
deal of kinetic energy is lost during the collision.
The objects are so deformed by the collision that they
stick together
Info
Box #3
Rockets
are perfect example of an Impulse producing a
change in momentum. Yet the forces for a rocket
are internal-- inside the system . So the total
momentum of the closed rocket system is always
a constant. See the amazing video below!
Why is "momentum" important ?