Forces & Interactions Vocal Flashcards
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
Three most common types of interaction
Touch
Gravity
Friction
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
Net Force
The overall force that remains after all “cancelling” of forces has been taken into account.
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.)
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 to sliding surfaces by coating the surfaces with a ______________.
Lubricant
(oil, grease. etc)
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 objecst have an effect upon each other.
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.
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
Air resistance
The force, caused by the air, opposing the motion of an object.
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.
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.”
An object that is “falling freely” is
in free fall.
(Has only one force acting upon it…gravity)