Motion Along a Straight Line Flashcards

Vocabulary based on Chapter 2 lecture notes covering displacement, velocity, acceleration, and freely falling bodies.

Average Velocity

The ratio of the displacement vector $\Delta x$ to the time interval $\Delta t$, which results in a vector quantity that has the same direction as the displacement.

Graphical interpretation of Average Velocity

The slope of the line joining the initial and final points on a graph showing position $x$ versus time $t$.

Instantaneous Velocity

The slope of the tangent line to the position versus time curve ($x-t$ graph) at the instant of interest.

Slope Steepness (x-t graph)

The steeper the slope (positive or negative) of an object's $x-t$ graph, the greater is the object's speed in the positive or negative $x-direction$.

Graphical Interpretation of Displacement

The area under the velocity versus time curve ($v-t$ graph) during a specific time interval.

Average Acceleration

The ratio of the change in velocity $\Delta v$ to the time interval $\Delta t$, resulting in a vector that points in the same direction as the change in velocity.

Instantaneous Acceleration

The slope of the tangent line to the velocity versus time curve ($v-t$ graph) at the instant of interest.

Speeding up

Occurs when the velocity vector and the acceleration vector point in the same direction.

Slowing down

Occurs when the velocity vector and the acceleration vector point in opposite directions.

Freely Falling Bodies

Any object moving only under the influence of gravity, regardless of its initial motion.

Free Fall Acceleration ($g$)

The magnitude of the acceleration near the surface of the Earth, which is given by $g = 9.8\,m/s^2$.

Kinematics by Integration

A method used to calculate velocity and position as functions of time when the acceleration of a body is not constant but is a known function of time.