HTET (PYIN NYAR YEIK) PRIVATE HIGH SCHOOL Physics Notes - Distance, Displacement, and Motion

HTET (PYIN NYAR YEIK) PRIVATE HIGH SCHOOL: Motion Fundamentals

Distance and Displacement

  • Distance

    • Verbatim Definition: Distance (or) distance travelled by the body is the length of the path along which the body moves.
    • Directionality: Distance has no specific direction.
    • Physical Quantity Type: It is a scalar quantity.
    • Standard Measurement: The SI unit of distance is meter (mm).

  • Displacement

    • Verbatim Definition: Displacement is the distance travelled along a particular direction.
    • Directionality: Displacement has a specific direction.
    • Physical Quantity Type: It is a vector quantity.
    • Standard Measurement: The SI unit of displacement is meter (mm).

Average Speed and Average Velocity

  • Average Speed (vavv_{av} or vˉ\bar{v})

    • Verbatim Definition: The average speed, vavv_{av} (or) vˉ\bar{v} is the ratio of total distance to time taken.
    • Physical Quantity Type: It is a scalar quantity.
    • Mathematical Formula:vav=stv_{av} = \frac{s}{t}         (or)         vˉ=st\bar{v} = \frac{s}{t}
    • Variable Definitions:
      • vavv_{av} (or) vˉ=average speed\bar{v} = \text{average speed}
      • s=distances = \text{distance}
      • t=time takent = \text{time taken}
    • Standard Measurement: The SI unit of Average speed is m/sm/s (Transcribed in source as m's).

  • Average Velocity (vavv_{av} or vˉ\bar{v})

    • Verbatim Definition: The average velocity vavv_{av} (or) vˉ\bar{v} is the ratio of total displacement to time taken.
    • Physical Quantity Type: It is a vector quantity.
    • Mathematical Formula:vav=stv_{av} = \frac{s}{t}         (or)         vˉ=st\bar{v} = \frac{s}{t}
    • Variable Definitions:
      • vavv_{av} (or) vˉ=average velocity\bar{v} = \text{average velocity}
      • s=displacements = \text{displacement}
      • t=time takent = \text{time taken}

Instantaneous Speed and Velocity

  • Instantaneous Speed

    • Verbatim Definition: The instantaneous speed is defined as the time rate of change of distance.
    • Mathematical Definition:Instantaneous speed, v=lim⁡Δt→0ΔsΔt\text{Instantaneous speed, } v = \lim_{\Delta t \to 0} \frac{\Delta s}{\Delta t}v=dsdtv = \frac{ds}{dt}

  • Instantaneous Velocity

    • Verbatim Definition: The instantaneous velocity is defined as the time rate of change of displacement.