Conservation of Momentum Flashcards
(25 cards)
It is inertia in motion
Momentum
Momentum is conserved for all collisions as long as external forces
don’t interfere
A moving object can have a _______________________ if it has a large mass, a
high speed, or both.
large momentum
Momentum is a _________ quantity
vector
A particle’s momentum has the same direction as its
velocity
The common unit for momentum is
kg m/s
If the momentum of an object is tripled, the kinetic energy will
increase by the factor of 9
On the other hand, if the kinetic energy of an object is quadrupled, its
momentum will
change by a factor of 2
When two objects of different mass have the same kinetic energy, the
object with _________ mass has greater momentum.
greater
Momentum can be expressed in terms of Newton’s _________ law of motion.
Second
is defined as the change of momentum experienced by a
body.
Impulse
The change in momentum depends on the
force that acts and the
length of time it acts.
If the momentum of an object changes, either the
mass or the velocity or both change
apply the greatest force
possible for as long as possible.
To increase the momentum of an object
If the change in momentum occurs over a long time, the force of
impact is
small
The same impulse does not mean the same amount of force or the
same amount of time—it means
the same product of force and time.
When a dish falls, will the impulse be less if it lands on a carpet than if
it lands on a hard floor?
No. The impulse would be the same for both surfaces because the
same momentum change occurs for each. It is only the force that is
less for the impulse on the carpet because of the greater time of
momentum change.
In every case, the momentum of a system cannot change unless it is
acted on by
external forces
In conservation of momentum, the initial sum of the momenta of two
objects will always be equal to the
final sum of their momenta
If the vector sum of the external forces on a system is zero, the total
momentum of the system is constant and is
conserved
For any system, the forces that the particles of the system exert on
each other are called
internal forces
Forces exerted on any part of the system by some object outside it
are called
external forces
When two bodies collide and both the momentum and energy are
conserved, it is called
elastic collision
If the forces between the bodies are also conservative, so that no
mechanical energy is lost or gained in the collision, the total kinetic
energy of the system is
the same after the collision as before
