9TH GRADE · KINEMATICS
Uniformly accelerated motion and its graphs
Acceleration, instantaneous velocity, displacement and graphical methods.
The entire theory of the lesson is collected here; you can read it without an account. In interactive mode, the same theory appears as cards, followed by questions. with checking the answer and task, and progress is saved.
Basic Concepts
Instantaneous speed
The speed of a body at a given moment in time, directed tangentially to the trajectory.
The average ground speed is equal to the distance over time, the average speed of movement is related to the movement vector, and the speedometer shows the instantaneous module.
Graphic methods of kinematics
The slope of the coordinate graph is related to the velocity, and the area under the velocity graph gives the displacement.
The slope of the velocity graph is equal to the acceleration, so the sign of the slope indicates acceleration or a change in speed in a negative direction.
Uniformly accelerated motion
Movement in which the velocity vector changes equally over equal periods of time.
Constant acceleration gives a linear graph of speed and a parabolic dependence of the coordinate on time.
Physical quantities
Acceleration
Change in velocity vector per unit time.
Unit: meters per second squared ·
Lesson formulas
Acceleration
Acceleration is equal to the change in speed divided by the time of change.
Speed at constant acceleration
Velocity is equal to initial velocity plus acceleration times time.
Moving under constant acceleration
The displacement consists of a uniform part and an addition from constant acceleration.
Relationship between speed and displacement
Velocity squares are associated with acceleration and displacement without explicit time.
Related formulas
The same formulas in the reference, with symbols and units.
Tasks on the topic
Statements, answer options and the walkthrough.