Select a coordinate system with only the Ox axis

average speed

instantaneous speed

average acceleration

instantaneous acceleration

Simultaneity is absolute

The time interval is also absolute

"At the same time": the length of the rod in the remote movement direction is the same as the time when the rod is at rest.

Premise: , that is, under the conditions of classical mechanics

Absolute motion: the motion of a particle relative to the basic reference system Relative motion: the motion of a particle relative to the motion reference system Involved motion: the motion of the motion reference frame relative to the basic reference frame

Different from linear motion, the particle plane motion needs to be determined by Two independent scalar functions x(t) and y(t) determine

on the contrary,

kinematic equations

Shoot high:

Range:

Acceleration of circular motion:

General curved motion:

position vector

kinematic equations

trajectory equation

Definition: The vector from the initial position of the particle point to the final position after t is called the displacement in time t

Orthogonal decomposition:

Distance: The total length of the path traveled by a particle on its trajectory within a period of time