Studied by 0 people
Looks like no one added any tags here yet for you.
momentum
The tendency for an object to KEEP MOVING – inertia in motion
Is Momentum a scalar or vector quantity?
Vector! Velocity is used to calculate it, and magnitude is taken into account
Momentum is _____ proportional to both MASS and VELOCITY!
directly
impulse
Change in momentum – when a force is applied to an object over time.
Does momentum and impulse have the same
units?
YES! A N•s is THE SAME unit as a kg•m/s!
the Impulse-Momentum Theorem
Any impulse on an object will change its momentum
A large impulse occurs when a large force acts in a ____ time or a small force acts over a ____ time
short, longer
an object which is moving at a ______ speed has momentum
constant
two objects of different mass are moving at the same speed; the more massive object will have the GREATER ______
momentum
impulse is a _____ quantity
vector
“subject to the force of gravity” meaning? impulse?
gravity is pulling it DOWNWARDS.. Impulse is NEGATIVE
an object’s momentum varies _____ with its speed
directly
if an object has momentum, then it also as ____ ___
mechanical energy
2 objects with different mass have the same momentum.
The ____ one will have the GREATEST ___ __
smaller, kinetic energy
objects involved in ____ encounter ____
collisions, impulses
an object that experiences a net impulse will experience a _____ ___
momentum change
in a collision, the net impulse experienced by an object is _____ to its momentum change
equal
two colliding objects will exert ____ forces upon eachother even when their mass is different
equal
a collision has an object encounter an ____ and a ____ __ ____
impulse, change in momentum
a particular collision lies along the contiuum is dependant upon the amount of ____ __ that’s conserved by the two objects
kinetic energy
elastic collisions occur when the collision force is a _____ force
non-contact
In an inelastic collision, some of the kinetic energy is converted into other forms of energy like:
sound, light, thermal energy, etc.
the ____ a ball rises upon collision with the ground when dropped, the ____ elastic that the collision is
higher, more
for increased momentum, ____ force is applied for as long as possible
greater
is more or less contact time good?
MORE
the force or impulse must be exerted on the object by something ____ the object
outside
if no outside force is there, there is __ change in momentum
NO
system
a defined collection of objects
closed system
No objects enter or leave (no gain/loss of mass)
isolated system
No external forces act on system (or the net = zero)
Law of Conservation of Momentum
the momentum of any closed, isolated system does not change –the number of objects does not matter, as long as no objects enter or leave the system and there is no net external force on the system.
internal forces
-forces between objects within a system
-CANNOT change the momentum of a system
external forces
forces exerted from outside a system
elastic collisions
-collisions in which both momentum and kinetic energy are conserved
-The total system kinetic energy before the collision equals the total system kinetic energy after the collision
inelastic collisions
-total system kinetic energy is not conserved (momentum IS conserved!)
-The total kinetic energy before the collision is not equal to the total kinetic energy after the collision
-A large portion of the kinetic energy is converted to other forms of energy such as sound energy and thermal energy
-sum of KE is reduced
are many collisions are either completely elastic or completely inelastic?
no!
when no external force is acting, the momentum of the system is ____
conserved
which quantities do not always occur in equal and opposite pairs when an interaction takes place within a system?
accelerations
2 ways impulse can be increased
1) increasing the force’s size
2) increasing the amount of time the force is acting
airbag problem 14
the airbag slows the driver’s forward momentum so that the same forward force is SPREAD OUT over a LONGER TIME INTERVAL
