8th Grade Science: Motion, Velocity, and Acceleration

Vocabulary flashcards covering speed, velocity, acceleration, vector and scalar quantities, and their standard units and formulas.

Speed

How fast an object moves. It is a scalar quantity, meaning it only has magnitude (a number value) and no direction.

Scalar Quantity

A quantity that only has magnitude (a number value) and no direction.

Velocity

Speed in a specific given direction. It is a vector quantity that measures the rate of change of position in a specific direction.

Vector Quantity

A quantity that has both magnitude (speed) and direction.

Acceleration

The rate at which velocity changes over time, encompassing any change in speed or direction.

Meters per Second ($\text{m/s}$)

The standard SI unit for velocity.

Meters per Second Squared ($\text{m/s}^2$)

The standard SI unit for acceleration.

Speeding Up (Positive Acceleration)

A condition where velocity and acceleration are in the same direction.

Slowing Down (Negative Acceleration / Deceleration)

A condition where velocity and acceleration are in opposite directions.

Changing Direction

A form of acceleration where velocity changes due to a direction change, even if speed remains completely constant.

Velocity Formula

The mathematical formula $v = \frac{d}{t}$, representing velocity equals displacement divided by time.

Acceleration Formula

The mathematical formula $a = \frac{v_f - v_i}{t}$, where acceleration equals final velocity minus initial velocity divided by time.

$$v_f$$

The variable representing final velocity in the acceleration formula.

$$v_i$$

The variable representing initial (starting) velocity in the acceleration formula.