Chapter 2: One Dimensional Kinematics (Straight Line Motion)

Kinematics

Kinematics

Deals with the concepts that are needs to describe motion. How things move in a straight line.

Dynamics

The effect that forces have on motion.

$x_{0}$

initial position

$x$

final position

$\Delta$

“change in”

final - initial

$\Delta x=x-x_{0}$

Equation for displacement

One-dimensional kinematics

Deals with motion along a straight line, considering only one direction.

Displacement

The change in position of an object. It is a vector quantity, having both magnitude and direction. Symbolized by Δx.

Velocity

The rate of change of displacement. It is a vector quantity, having both magnitude and direction. It is calculated as the displacement divided by the elapsed time.

$\overrightarrow{v}=\dfrac{\Delta \overrightarrow{x}}{\Delta t}$

Equation for average velocity

moving in the positive direction

If average velocity is positive, the object is…

moving in the negative direction

If average velocity is negative, the object is…

not moving

If average velocity is zero, the object is…

$v=$ total distance/total time

Equation for average speed

Speed

The rate of change of distance traveled. It is a scalar quantity, having only magnitude. It is calculated by the total distance traveled divided by the time taken.

Acceleration

The rate of change of velocity. It is a vector quantity, having both magnitude and direction. It is calculated as the change in velocity divided by the time taken.

increasing with time

If average acceleration is positive, the speed is…

decreasing with time

If average acceleration is negative, the speed is…

at constant speed

If average acceleration is zero, the speed is…

Equations of Motion

The equations that relate displacement, velocity, acceleration, and time.

$x$

Variable for displacement

$a$

Variable for acceleration

$v$

Variable for velocity

$v_{0}$

Variable for initial velocity

$t$

Variable for time

Free fall

All bodies at the same location above the Earth fall vertically with the same acceleration.

Acceleration due to gravity

The motion of free fall and the acceleration of a freely falling body

-9.80 m/s²

Acceleration (a) is equal to

9.80 m/s²

Acceleration due to gravity (g) is equal to