Physical Science - Kinematics Vocabulary

Vocabulary flashcards covering the key terms, definitions, and equations of kinematics from Lesson 7 of Physical Science.

Kinematics

The branch of mechanics that describes motion in terms of displacement, velocity, and acceleration.

Dynamics

The branch of mechanics that relates force and motion.

Translation

Motion in a straight line, commonly described by displacement, velocity, and acceleration, where the origin of the Cartesian coordinate system is considered the start of motion.

Scalar quantities

Quantities that can be described completely by their magnitude and appropriate unit.

Vector quantities

Quantities that are completely described by their magnitude, appropriate unit, and direction.

Distance ($d$)

The length of the path taken by a body in moving from its initial to its final position.

Displacement ($d$)

A vector quantity with a direction pointing from the initial to the final position and a magnitude equal to the straight-line distance between those positions.

Speed

A scalar quantity that serves as a measure of how fast a body moves.

Average speed ($v$)

The total distance traveled by a body per unit time of travel, calculated using $v = \frac{\text{Total distance traveled, } d_{\text{total}}}{\text{Total travel time, } t}$ or $v = \frac{\text{A}d}{\text{A}t} = \frac{d - d_0}{t - t_0}$.

Instantaneous speed

The speed of a body or vehicle at a given instant, such as the value indicated by a speedometer.

Velocity ($v$)

A vector quantity defined as the displacement of a body per unit time.

Average velocity

The total displacement per unit time.

Acceleration ($a$)

A vector quantity that refers to the change in velocity with respect to time, expressed in symbols as $a = \frac{\text{A}v}{\text{A}t} = \frac{v - v_0}{t}$.

Acceleration (Physics usage)

The physics definition stating that an object is accelerating whenever it is slowing down, speeding up, or changing direction.