CONSERVATION OF MOMENTUM IN ONE DIMENSIONAL COLLISIONS
____________ is used for calculations when objects ______ (like a car crash) or objects push off from each other (like a bullet pushing out of a gun).
___________ is one of the Universes' ______________ quantities.
This means that the amount of momentum the Universe had at its ________ is the exact same amount it has _____ and will be the same _________. In other words, momentum can never be _________ or _________, it can only be moved from one place to another. So, if one object's momentum ___________ that can only happen because it TOOK that momentum from another object! (do you see why this property makes momentum useful for collision problems? If one object ______ 40 units of momentum, it means the object it collided with _______ those 40 units! The math ends up being simple addition and subtraction)
-The Momentum Equation comes from __________
1) F=ma with ___________
becomes
2) F=m(v/t) now move the "t" to the other side and you get
3) Ft=mv
-Ft=mv is called the Impulse Eqn.
-It describes the Time and Force of Impact for an object _____________ something.
-For the object, "m"+"v" are CONSTANT. (in this example)
So, only "F"+"t" can change and if ____________ the other must __________ to compensate (Air Bags ________ the impact time so the __________ on the person drops).
-This is also a reason for a "_____________" in sports. The longer the ______ of Impact, the greater the imparted ___________. (as ____ goes up, ____ goes up)
-MOMENTUM is p=mv and It is a ____________. (Why "p"?)
-This means that when objects __________ you can calculate their velocity, mass and/or ______________.
'p' before = 'p' after
or
mb * vb = ma * va
This is the equation used if an object __________ something (i.e. gun) or one object pushes off from another or 2 objects collide and _____________ stop.
There ________ types of collisions if the objects don't stop:
1) ELASTIC-Here the colliding objects __________ _____ each other.
2) INELASTIC-Here the colliding objects _________ ___________. (So you ADD their masses and they have only ONE velocity.)
ELASTIC COLLISIONS-The total change in Mom.=0 (meaning _________ is _______)
INELASTIC COLLSIONS-Total change in Mom.=0 (meaning _________ is _______)
-Collision problems are worked with the idea that MOMENTUM __________ the collision ___________ the momentum after:
-But you have to have two objects to have a ___________, so you need a BEFORE and AFTER for _______ object. The ___________ on the AFTER side are denoted by an accent mark called a "________." It looks like '
S0:
BEFORE = AFTER
To set these up, make two columns with two "m"'s and two "v"'s
BEFORE AFTER
m1= m1=
m2= m2=
v1= v1'=
v2= v2'=
USUALLY, m1 and m2 are _____ __________ before and after the collision (i.e. The objects didn't break, shatter, explode, etc.)
After you set this up, there should be only ONE variable you are missing. Solve for that one, using
m1* v1 + m2* v2 = m1* v1' + m2* v2' if they ________ stick together!
(this is the __________ collision equation)
or m1* v1 + m2* v2 = (m1 + m2)* v'1+2 if they ________ stick together!
(this is the __________ collision equation)
What can happen in an _______ collision?
Let's say a cue ball hits another billiard ball that's ___ _____. One of ______ things will happen depending on the masses of the balls:
1) If the cue ball and the billiard ball are the _____ mass (m1 __ m2), then the cue ball will _____ completely and the billiard ball will move at the ______ speed the cue ball had.
2) If the cue ball has ______ mass than the billiard ball (m1 __ m2), then the cue ball will slow down but still be going _______ and the billiard ball will move __________.
3) If the cue ball has ______ mass than the billiard ball (m1 __ m2), then the cue ball will bounce ____________ and the billiard ball will move __________.
What can happen in an Inelastic collision?
Here the 2 balls stick to each other after they hit- maybe they're wrapped in Velcro©. (by the way, there's a myth that NASA created Velcro- not true, the patent on Velcro is 3 years before the space agency was even created.)
Only one thing will happen: the cue ball will slow down and the billiard ball will speed up. Or you could say the combined balls' speed will be less than the cue ball
(v1+2 < v1)