The following NOTATION will be used throughout PHY 203 and PHY 204

  1. 'x' stands for 'position' measured on some line of space, i.e.: position on ONE Dimension or "AXIS" (such as the X-axis) of space.

  2. 't' stands for 'time'.

  3. 'v' stands for 'velocity'.

  4. Any variable name or symbol written with a horizontal bar above it stands for the average value of that variable (over some time interval).

    v with a bar above it refers to 'average velocity', etc.

  5. A symbol written without a bar above it refers to the variable value at one instant in time.

    v with nothing above it refers to 'instantaneous velocity'.

  6. If the subscript zero is seen to the right of a symbol, then the symbol refers to the variable value at t=0.

    In other words, it refers to the instantaneous value of that variable at the beginning of whatever period of time we're interested in.

    v0 is read 'v-naught' and means the starting or 'initial' value of velocity.
    This is a particular example of instantaneous velocity.