Presentation on theme: "Kinematics Kinematics is the branch of physics that describes the motion of points, bodies (objects) and systems of bodies (groups of objects) without."— Presentation transcript:
Kinematics Kinematics is the branch of physics that describes the motion of points, bodies (objects) and systems of bodies (groups of objects) without consideration of the causes of motion.
Kinematics One-dimensional kinematics. Movement along one axis. Distance – the total distance traveled from beginning to end. It always has a positive value. A scalar quantity – completely characterized only by magnitude. Displacement – the change in position. A vector quantity completely characterized by magnitude and direction.
Kinematics Average speed – distance divided by elapsed time. Average velocity – displacement divided by elapsed time. Some units for speed and velocity are and any unit of length divided by a unit of time.
Kinematics Instantaneous speed – the speed at a given instant. Instantaneous velocity – the velocity at a given instant.
Kinematics Average acceleration – the change in velocity divided but the change in time.
Kinematics Instantaneous acceleration – the acceleration at a given instant.
Kinematics Constant acceleration – when acceleration is constant, instantaneous acceleration is equal to the average acceleration. In this course we will only be dealing with situations involving constant acceleration.
Kinematics In the following slide the subscript i refers to an initial condition, and the subscript f refers to a final condition.
Table 2-4 Constant-Acceleration Equations of Motion Variables RelatedEquation Velocity, time, acceleration v f = v i + at Initial, final, and average velocity v av = ½(v f +v i ) Position, time, velocity d = ½(v f +v i )t Position, time, acceleration d = v i t +½ at 2 Velocity, position, acceleration v f 2 = v i 2 + 2ad