Lesson-11.-Kinematics-1

Kinematics: Motion Along a Straight Line

Overview

• Kinematics is a branch of classical mechanics that deals with the study of motion of objects without considering the forces that cause the motion.

• Developed and outlined by Isaac Newton.

Key Concepts Related to Kinematics

• Position

• Time

• Distance

• Speed

• Velocity

• Displacement (including Average and Instantaneous)

Position

• The location of an object (or particle) from a reference point, usually denoted as x.

• Notation:

  • xi: Initial position

  • xf: Final position

Example Scenario

• If the office building is set as the reference point:

  • Positions of the man (xm) and the store (xs) can be noted on a number line:

    • For example, at -25, -20, -15, -10, -5, 0, 10, 15, 20.

Distance

• A scalar quantity that measures the total path length traveled by a particle moving from one location to another.

Example Calculation

• If a man travels to the store then returns to the office:

  • The total distance traveled can be calculated using segments d1 and d2 while considering their positions on a number line.

Displacement

• A vector quantity that pertains to the straight path length from the initial position to the final position, represented by the formula:

  • Displacement = xf - xi.

Example Calculation

• For the man who goes to the store and then returns to the office:

  • Displacement can be calculated based on initial and final positions along a number line.

Time

• A scalar quantity that measures the duration of events.

Average Speed

• A scalar quantity defined as the ratio of total distance traveled to the total time taken.

  • Formula:

    • Average Speed = Total Distance / Total Time.

Example Calculation

• In the scenario where the man goes to the store (30 seconds) and then rushes back (10 seconds), his average speed can be calculated based on these times.

Average Velocity

• A vector quantity defined as the ratio of total displacement to the time during which the displacement occurs.

  • Formula:

    • Average Velocity (vave) = ∆x / ∆t.

Example Calculation

• The average velocity can be calculated using the man's total displacement after taking into account the time taken for the journey.

Instantaneous Velocity

• A vector quantity that indicates how fast an object is moving at a specific point along its path.