Unit 1: Kinematics

• Definition: Kinematics is the branch of mechanics that describes the motion of points, bodies, and systems of bodies without considering the forces that cause the motion.

• Key concepts include:

  • Displacement: A vector quantity that refers to the change in position of an object.

  • Velocity: The rate of change of displacement with respect to time, expressed as a vector.

  • Acceleration: The rate of change of velocity with respect to time, also a vector quantity.

Position-Time Graphs (Displacement vs. Time)

• Constant Velocity

  • The graph is a straight line with a constant slope.

  • Positive slope: motion in the positive direction.

  • Negative slope: motion in the negative direction.

• Acceleration

  • The graph curves upwards (for increasing velocity) or downwards (for decreasing velocity).

• Stationary Object

  • The graph is a flat line (slope = 0).

Velocity-Time Graphs (Velocity vs. Time)

• Constant Velocity

  • The graph is a horizontal line.

• Acceleration

  • The graph is a straight line with a constant slope.

  • Positive slope: positive acceleration (speeding up).

  • Negative slope: negative acceleration (slowing down).

• Deceleration

  • The line can cross the time axis, indicating a change in direction.

• Area Under the Graph

  • The area under the velocity-time graph provides the displacement of the object during that time interval.