Forces and Interactions Vocabulary Flashcards
______________ is a science word. It is used to sort of describe how much of an impact an object might make in a collision.
Momentum.
Momentum = Mass x Velocity
Definition of Mass
The amount of matter in an object.
(Each time you add an atom to an object, you add mass)
Definition of Weight
The force of gravity upon an object.
Mass and Weight mean ____________ things.
Different
Formula for finding Weight
Weight = ___________ x ____________
Weight = mass x gravity
What is this thing?
(scroll down and look at entire picture)
Your secret weapon to get 4 questions right on the upcoming test.
What can this tell you about mass and weight?
The Earth’s gravity applies a force of
9.8-Newtons to a 1-kg mass
If you took this thingy to the moon and looked at it, the mass would _______________?
Stay the same.
The 1-kg label on th object will still say 1-kg, and it will still be correct.
If you took this thingy to the moon and looked at it, the weight would _______________?
Go down.
The moon has less gravity, so the red needle would only point to about 2.
What can this thingy tell you about weight?
Weight is a force.
The force of gravity upon an object
weight
Two definitions of acceleration
Change in speed or direction
or
Change in Velociy
Formula for acceleration
Accleration =
Acceleration = change in velocity/change in time
can also be written as:
a = Δv / Δt
Mass means pretty much the same thing as ________
Inertia
If there is no air friction, which would experience a greater acceleration when dropped off a cliff, a large rock or a small rock?
Neither, both would accelerate at the same rate, and both would reach the ground at the same time.
Gravitational Field Strength near the Earth’s surface
9.8 newtons/kilogram
The word “static” means….
at rest
Static Friction means
The force of friction preventing a motionless object from moving.
Sliding Fricition means…
The force of friction impeding the motion of an object sliding across a surface.
Air Friction
The force of friction impeding the motion of an object fighting its way through the air.
(It has to bump the air molecules out of the way)
You can reduce the friction between two sliding surfaces by coating the surfaces with a ______________.
Lubricant
(oil, grease. etc)
What are these things?
Ball Bearings
(You have these on your bicycle, on your skateboard, inline skates, cars, etc.)
(These are what allow wheels to roll with very little friction.)
What would happen to your mass if you left Earth and went to Jupiter?
Nothing.
Mass is a measure of how much “stuff” or matter there is in an object.
What would happen to your weight if you left Earth and went to Jupiter?
Your weight would go up.
Jupiter has a much stronger gravitational field than the Earth. Weight is the pull of gravity upon an object.
Interaction
When two objects have an effect upon each other.
Three most common types of interaction
Touch
Gravity
Friction
What does this stand for?
ΣF
Sum of Forces
Sum of Forces, or ΣF, means the same thing as:
Net Force
Friction
The force impeding the motion of an object scraping across a surface or plowing through the air.
Kinetic Friction
The force impeding the motion of a moving object.
Net Force
The overall force that remains after all “cancelling” of forces has been taken into account.
Unbalanced Force means that the Net force is ___________.
Non-Zero
Normal Force
A force at right angles to a surface
A force that is perpendicular to a surface
Normal Force
Equilibrium
When all forces upon an object cancel out.
If an object has a constant velocity, what other things do you know?
Net Force = Zero
Acceleration = Zero
Sum of Forces = Zero
Its in Mechanical Equilibrium
If an object has a Net Force = Zero, what other things do you know?
It has a constant velocity
Acceleration = Zero
Sum of Forces = Zero
Its in Mechanical Equilibrium
If an object has an acceleration of zero what other things do you know?
It has a constant velocity
Net Force = Zero
Sum of Forces = Zero
Its in Mechanical Equilibrium
If the Sum of Forces upon an object is zero, what other things do you know?
It has a constant velocity
Net Force = Zero
Acceleration = Zero
Its in Mechanical Equilibrium
If an object is in equilibrium, what other things do you know?
It has a constant velocity
Net Force = Zero
Acceleration = Zero
Sum of Forces = Zero
Uniform Acceleration
A constant, steady acceleration caused by a constant, steady net force.
(Hint, in high school science, all accelerations studied will be uniform.
An object is in free fall when….
the only force acting upon it is gravity.
(The object could be going up, sideways, or down)
An object has been thrown upward. The only force acting upon the object is gravity. We would say that this object is…
in free fall.
An object has been thrown sideways off of a cliff. The only force acting upon the object is gravity. We would say that this object is…
in free fall.
An object that is “falling freely” is
in free fall.
(Has only one force acting upon it…gravity)
Resistance
The act of opposing something.
Air resistance
The force, caused by the air, opposing the motion of an object.
Gravity
A force that exists between ANY two objects that have mass.
Earth’s Gravitational Field
The area around the Earth that is influenced by the Earth’s gravity.
(Put an object in Earth’s gravitational field and it will tend to “fall” toward the Earth)
Moon’s Gravitational Field
The area around the Moon that is influenced by the Moon’s gravity.
(Put an object in the Moon’s gravitational field and it will tend to “fall” toward the Moon)
Jupiters’s Gravitational Field
The area around Jupiter that is influenced by Jupiter’s gravity.
(Put an object in Jupiter’s gravitational field and it will tend to “fall” toward Jupiter)
What is the strength of Earth’s gravitational Field
9.8 N/kg
This means that the Earth will apply a gravitational force of 9.8 newtons for every 1 kilogram of mass.
Inclined Plane
A hill.
(A plane is a flat surface. If it is inclined, you have a hill)
The purple part below.
Inclined Ramp
An angled surface you might push or pull an object up.
In the picture below, the box is being pulled up the green “Inclined Ramp.”
Both of these cars were going 35-mph before the collision, why did the Smart Car lose?
Momentum = Mass x Velocity
The smart car has less mass, so it has less momentum.
What are these?
These are the SI fundamental units.
What are the fundamental units of speed?
meters / second
What are the fundamental units of force?
kg • m/s2
(Kilograms times meters per second squared)
(notice that this is a combination of the fundamental units in the table below)
What are the fundamental units of time?
s
(seconds)
What are the fundamental units of acceleration?
m/s2
(meters per second squared)
(notice that this is made up of “fundamental units” from the table below)
Reaction Time
The interval between a stimulus and your response.
Example:
The time between when you see a mouse and when you scream.
What are the fundamental units of mass?
kg
(kilograms)
“At Rest”
Not moving
“follows a straight-line-path”
moves in a straight line
Inertia
An object’s resistance to a change in velocity.
(Means almost the same thing as mass)
Density
mass/volume
(So, in order to calculate the density of an object, you divide its mass by its volume)
Order the following items from least dense to most dense.
Rock
Styrofoam
Lead
Water
Styrofoam
Water
Rock
Lead
Volume
How much space an object takes up.
What is the “water displacement method” for determining the volume of an object?
Put water in a container. Submerge the object in the water. See how much the water rises.
“Weigh an Object”
Using a scale to find out how much gravity is pulling down upon an object.
(Note: the reading on the scale would change if you went to the moon.)
“Mass an Object”
Using a balance to determine the mass of an object.
(Note: if you took this to the moon, the balance would still read the same amount. Why?)
Constant Speed
**Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding!Ding! Ding! Ding! Ding! Ding! Ding!Ding! Ding! Ding! Ding! Ding! Ding!Ding! **
Net Force = 0
Sum of Forces = 0
Its in Equilibrium
Newton’s First Law
Acceleration = 0
Blah blah blah blah blah bladdady blah constant speed blah blah blah blah blah blah yada blah.
Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding!Ding! Ding! Ding! Ding! Ding! Ding!Ding! Ding! Ding! Ding! Ding! Ding!Ding! Ding! Ding! Ding! Ding! Ding!
Net Force = 0
Sum of Forces = 0
Its in Equilibrium
Newton’s First Law
Acceleration = 0
Yadda blah, yackity yack blahdidy blah, at a constant velocity blah yaddidy blah yabba dabba do diddtily bloogalsnort.
Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding! Ding!Ding! Ding! Ding! Ding! Ding! Ding!Ding! Ding! Ding! Ding! Ding! Ding!Ding! Ding! Ding! Ding! Ding! Ding!
Net Force = 0
Sum of Forces = 0
Its in Equilibrium
Newton’s First Law
Acceleration = 0
Satellite
Any object that orbits the Earth
(Spaceships, the moon, asteroids, etc)
Non-Zero
Not equal to zero
“Applied”
Put upon.
“A 13-N force was applied to a rock,” means that you pushed or pulled on the rock with a force of 13-N.
Frictionless
No friction AT ALL.
Even more slippery than the slipperiest ice!
“Releases”
Drops
This would mean that you didn’t “throw” the object down, so it starts with an intitial velocity of zero.
“Released”
Dropped
(Again, initial velocity is zero)
“Drops”
Not thrown up or down.
(If a boy “drops” a rock off a cliff, the initial velocity would be zero)
“Throws”
Gives an initial velocity to.
(Can be up, down, or any other direction)
Suspended
Hanging From
“Acted Upon”
“To exert or have an effect upon.”
A force of 20 Newtons “acted upon” the the block to the right.
Variable
Changing
A “variable” horizontal force acted upon the object.
What does the word, “experience” mean in the following context?
The object “experienced” a lot of friction.
It means “encountered” or “was subjected to.”
The object “encountered” a lot of friction
The object “was subjected to” a lot of friction.
Towed
Pulled
What does “neglecting” mean in the following sentence?
“Neglecting” air friction, the Earth’s gravitational field causes object to accelerate at 9.8 m/s2.
It means “Ignoring”
“neglecting air friction,” means the same thing as “ignoring air friction.”
What is this?
Its a bottle rocket!
(Rockets like this are often used to illustrate Newton’s Third Law)
(Notice, the water shoots down, the rocket shoots up)
What does the word “falls” mean in the following sentence?
A rock “falls” from the edge of a cliff.
V0 = 0 m/s
“Falls” means that the rock was not thrown down or up. Thus, it has an intial velocity of zero.
What does the word “approximately” mean in the following sentence?
The weight is “approximately” 5-newtons
It means “close to” or “about.”
For example, if the weight is truly 4.9-newtons,
we could say it is “approximately” 5.0-newtons
or “about” 5.0-newtons.
What SI measurment unit would you use to measure weight?
Newtons
Weight is a force.
Defined as “the ability to cause a change.”
Energy
Stored Energy is often called
Potential Energy
In science, work is often defined as
The change in energy caused by a force.
Work = Force x Distance
What are two things you could change about a car that would increase its ability to accelerate?
Make it lighter
Make the engine more powerful.
Less mass means more acceleration and more force means more acceleration.
What is the ONLY reason some obects fall more quickly than others when released?
Air Friction!
If there were no air, ALL objects would fall at the same rate.
