Download Momentum – Concept Overview

Intro to Momentum Video:
Copy table, watch video, and fill
out table below
Momentum-related
terms
1.
2.
3.
4.
5.
6.
Examples of
Momentum
Cool facts about
momentum
Intro to Momentum:
Possible Answers
Momentumrelated terms
Examples of Momentum
Cool facts about
momentum
1. Inertia
Car crash and occupant keeps
going through windshield
No resistance in space
P=mv
2. Force, Acceleration Spaceship hit by laser and
keeps going
Can be used as
weapon/dangerous
3. Reaction
Ship fires rockets/launch
Mvbefore=mvafter
(collisions)
4. Mass
Astronaut pushes off spaceship
deck and moves in opposite
direction
Cant travel in space
without it
5. Velocity
Ship changing direction in midflight
Can be used as a tool for
our benefit
5. Conservation
Meteor explodes into tinier
pieces
F=ma
6. 3 Laws of Motion
Spacecraft launching gases
Once you get going you
Intro to Momentum
Inertia (I): The tendency of an object in motion to stay in
motion (as well as for a still object to stay still) ex.
spaceship keeps moving after it gets blasted.
Momentum (p): The product of an object’s mass(m)and
velocity(vvector) so p=mv. Can be:
– Linear: momentum of an object moving in a straight line
(pool ball on table)
– Angular: momentum of an object moving NOT in straight
line (rotation)
Newtons 3 Laws of Motion:
1.
Object in motion stays in motion or at rest stays at rest until
external force acts on it
2.
Acceleration of an object is proportional to the force applied
to that object (F=ma)
3.
For every force applied there is an equal and opposite
reaction force applied back.
Intro to Momentum
Law of Conservation of Momentum: In a closed system,
momentum before is same as momentum after (but may
seem different after…spaceship explosion)
mbeforevbefore=maftervafter
Momentum can be both positive and negative:
Good=propulsion used for movement in space, other?
Bad=Used as a weapon (impulse beams), other?
Impulse
Impulse: Is the product of a force that
acts on an object and the length of
time the force acts.
– Causes a change in momentum
• Mathematically: Imp = F x ∆t
• where F=force (N or lbs)
∆t = change in time (s) from
t2-t1
• Examples include hockey stick sriking puck, rocket lifting off, bullet hitting
watermelon
Momentum Intro Hmwk
Answer the following:
1.
What are the 2 variables that make up momentum?
2.
How is momentum determined mathematically?
3.
What are the 2 types of momentum? What is the difference
between them in terms of the motion of the object
involved?
4.
Why are Newton’s 3 laws important to momentum (i.e. how
is each law involved)?
5.
State in your own words, what the law of conservation of
momentum is about.
6.
How is a car crash an example of conservation of
momentum? How do you know momentum was conserved?
7.
What is meant by the term “impulse”?
8.
Based on the definition of impulse, how would you write its
meaning out mathematically? (formula)
9.
What comes first, impulse or momentum (assume object
starts at rest)?