Motion and Stability

speed

rate of change of position

motion

change in position

time

interval between two events

force

push or pull

distance

the space between two points

constant speed

speed that does not change

postitive acceleration

speeding up

negative acceleration

slowing down

acceleration

rate of change in speed

3 ways to accelerate

speed up, slow down, change direction

What axis is the time on in a distance-time graph?

x-axis

What axis is distance on in a distance-time graph?

y-axis

inertia

The tendency of an object to resist a change in motion

mass

the amount of matter in an object

matter

anything that takes up space and has mass

weight

A measure of the force of gravity on an object

Does mass or weight change depending on where you are?

Weight changes due to changes in gravity; mass does not change

How is weight measured?

spring scale

How is mass measured?

balance

Units for mass

grams

Units for weight

Newtons

Units for force

Newtons

Newton's Third Law of Motion

"For every action force

Action-Reaction Pair

Two forces of equal magnitude and opposite direction that act on two DIFFERENT interacting objects at the same time.

Collision Contact Forces

"During a collision between two objects

Collision Vector Model

A force diagram at the point of impact showing two arrows of equal length pointing in opposite directions on the colliding objects.

Acceleration Disparity in Collisions

"Even though colliding objects experience equal contact forces

1D Collision Forces

Contact forces during vertical or horizontal one-dimensional collisions remain equal and opposite between the two colliding objects.

Newton's First Law of Motion

"An object at rest remains at rest

Newton's Second Law of Motion

The acceleration of an object depends directly on the net force applied and inversely on its mass (F = ma).

Inertia

The tendency of an object to resist any change in its state of motion; directly proportional to the object's mass.

Mass

The amount of matter in an object; it measures an object's inertia and remains constant regardless of location.

Net Force

The vector sum of all individual forces acting on an object in a given dimension.

Balanced Forces

"Forces acting on an object that combine to equal a net force of 0 N

Unbalanced Forces

"Forces acting on an object that result in a non-zero net force

Effect of Doubling Net Force

Doubles the acceleration of the object if the object's mass remains constant.

Effect of Doubling Mass

Cuts the acceleration of the object in half if the net force remains constant.

1D Speed Changes

An object speeds up when net force acts in its direction of motion and slows down when net force opposes its motion.

Gravitational Force

"An attractive non-contact force that pulls objects with mass toward one another

Large Mass Gravitational Attraction

"Celestial bodies with immense mass (such as Earth

Center of Gravity Pull

Earth's gravitational force attracts all objects near its surface directly toward Earth's center.

Unit of Force

"Newton (N)

Free-Body Diagram

A visual diagram using force arrows (vectors) to display the magnitude and direction of all forces acting on an object.

Friction

A contact force that opposes the relative motion between two touching surfaces.

Methods to Increase Friction

Increase the roughness of the contact surfaces or increase the pressing force squeezing the surfaces together.

Normal Force

The support contact force exerted by a surface perpendicular to an object resting upon it.

Applied Force

A force directly exerted on an object by a person or another object.

Air Resistance (Drag)

A friction-like contact force exerted by air particles opposing the motion of an object passing through the air.

Weight

The measure of the gravitational force acting on an object's mass (measured in Newtons).

Difference Between Mass and Weight

"Mass stays constant everywhere in the universe

Triple-Beam Balance

A laboratory tool used to measure an object's mass in grams or kilograms.

Spring Scale

A laboratory tool used to measure force or weight in Newtons (N).

Speed

"The rate of change of position over time

Acceleration

"The rate of change of velocity over time (speeding up

Distance-Time Graph: Constant Speed

"Represented by a straight

Distance-Time Graph: Stationary Object

"Represented by a flat

Distance-Time Graph: Acceleration

Represented by a curved line indicating changing speed over time.