Physics 20 Unit 1: Velocity and Acceleration Flashcards

A comprehensive set of vocabulary flashcards covering kinematics, vector and scalar quantities, motion graphs, acceleration equations, and the principles of gravity based on Physics 20 Unit 1 notes.

Kinematics

The branch of physics that describes the motion of objects without looking at the cause of the motion.

Dynamics

The branch of physics that relates the motion of objects to the forces which cause them.

Scalar

A quantity that has magnitude (a number value) but no direction, such as time, mass, or distance.

Vector

A quantity that has both magnitude and direction, such as velocity, force, or displacement.

Quantitative measurement

A measurement based on the root word quantity that provides a number answer.

Qualitative measurement

A measurement that describes qualities of the data, such as color.

Origin

A reference point, usually designated as zero, located at the start of the motion of an object.

Distance

A scalar quantity representing the length of the path taken to move from one position to another, regardless of direction.

Displacement ($\Delta \vec{d}$)

A vector quantity representing the change in position of an object, calculated as final position minus initial position ($\vec{d}_f - \vec{d}_i$).

$\Delta$ (Delta)

The Greek letter used in physics formulas to mean "a change in…"

Position ($\vec{d}$)

The straight-line distance and direction of an object from the origin.

Speed ($v$)

A scalar quantity that represents the rate at which an object moves without considering direction.

Velocity ($\vec{v}$)

A vector quantity representing the rate of change of displacement, including magnitude and direction.

Average Velocity ($\vec{v}_{avg}$)

The overall velocity for an entire trip, calculated as total displacement divided by total time ($\Delta \vec{d} / \Delta t$).

Instantaneous Velocity

The velocity of an object at one specific moment of time, such as a reading on a speedometer.

Uniform Motion

Motion where the velocity of an object is always the same, also referred to as constant velocity.

Slope of a d-t graph

A property of a displacement-time graph that always equals the velocity of the object at that time.

Slope of a v-t graph

A property of a velocity-time graph that is equal to the acceleration of the object.

Area under a v-t graph

The calculation of velocity multiplied by time on a graph, which equals the object's displacement.

Acceleration ($\vec{a}$)

A vector quantity that measures the rate at which the velocity of an object changes ($\frac{\vec{v}_f - \vec{v}_i}{t}$).

Positive Acceleration

Occurs when an object is speeding up in the positive direction or slowing down in the negative direction.

Negative Acceleration

Occurs when an object is slowing down in the positive direction or speeding up in the negative direction.

Air Resistance

A type of friction identified by Galileo Galilei that causes objects of different masses to fall at different rates in the atmosphere.

Acceleration due to gravity ($a_g$)

The acceleration of any object in the absence of air resistance, which is approximately $-9.81\,m/s^2$ on Earth.

Gee's

A measurement comparing the acceleration an object is experiencing to the value of regular gravity ($9.81\,m/s^2$).

Colonel John Stapp

A U.S. Air Force officer and doctor who studied the effects of extreme acceleration on the human body, surviving an acceleration of $46.2\,g$.