Search
Create
Log in
Sign up
Log in
Sign up
Science Force and Motion Unit 3
STUDY
Flashcards
Learn
Write
Spell
Test
PLAY
Match
Gravity
you wont get in unless you know the password
Terms in this set (42)
Motion
when the distance from a reference point is changing; when an object changes position
Reference point
a basis or standard for evaluation, assessment, or comparison
Speed
the distance traveled over a period of time
Calculation of Speed
s=d/t
Velocity
speed but with a direction that you end up at (or speed in a given direction)
Calculation for Velocity
v=d/t with direction
Calculation For Acceleration
a=(vf-vi)/t
Acceleration
is any change in velocity (or velocity changes over time)
Positive acceleration
An increase in speed of an object.
Negative acceleration
A decrease in speed of an object.
Angular acceleration
is going in a circle; a change in direction.
Force
a push or pull
Calculation for force
F=m x a (formula)
Balanced Forces
when all forces cancel out and net force is zero.
Unbalanced Forces
the forces are not canceled out. This will be the direction the object goes.
Friction
a force that resists motion.
Gravity
the force that pulls an object toward a rotating body; the between all matter
Freefall
When the only force acting on a falling object is gravity
Weight
the force a mass applies downward because of gravty
Calculation for Weight
W=m x g
Newton's 1 Law of Motion
Inertia law:That an object's motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero.
Newton's 2 Law of Motion
a=F/m law: Newton determined that two factors affect the acceleration of an object: the net force acting on the object and the object's mass. The relationships between these two factors and motion make it up. This law states that the acceleration of an object equals the net force acting on the object divided by the object's mass.
Newton's 3 Law of Motion
Action/Reaction forces law: states that every action has an equal and opposite reaction. This means that forces always act in pairs. First an action occurs, such as the skateboarders pushing together. Then a reaction occurs that is equal in strength to the action but in the opposite direction. In the case of the skateboarders, they move apart, and the distance they move depends on how hard they first pushed together.
Momentum
a property of a moving object that makes the object hard to stop.
Calculation for Momentum
=mass x velocity
Law of Conservation of Momentum
The total momentum of any group of objects remains the same unless outside forces act on the objects.
When 2 objects collide in the absence of friction, momentum is not lost.
Acceleration Graph
X-axis is Distance, Y-axis is speed or velocity (speed up and speed down)
Non-contact forces
a pull or push created by object's field
Earths acceleration due to gravity
9.8 m/s2
static friction
the friction that keeps objects in place; the minimum amount of force needed to be overcome to start motion
sliding friction
friction when 2 surfaces rub against each other
rolling friction
friction when one surface rolls over another
fluid friction
friction when an object moves through matter that can flow
air resistance
friction that occurs when an object moves through the atmosphere
speed/velocity graph
y-axis: distance; x-axis: time
flat line on a speed graph
an object isn't moving
flat line on an acceleration graph
an object is staying at a constant speed
steeper line on speed graph
faster speed
inertia
the property of an object to resist a change in movement
factors affecting gravity
mass and distance
mass and gravity
larger mass means larger gravitational pull
distance and gravity
larger distance means less gravitational pull
;