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Formula Average Velocity Start position    End position    Start time    End Time

Formula
Formula: Average Velocity
Position-Time Graph and Average Velocity as Slope

Average velocity

Unit
The average velocity of a body, e.g. an airplane or a car. It is defined as the distance traveled \(\Delta s = x_2 - x_1\) per time \(\Delta t = t_2 - t_1\): \[ v ~=~ \frac{\Delta s}{\Delta t} \]The sign of the average velocity determines whether the body moves to the right (positive \(v\)) or to the left (negative \(v\)).

Example: The total distance is \( \Delta s = -20 \, \text{m}\) and the time taken is \( \Delta t = 4 \text{s} \). Then the average velocity is:\[ v ~=~ \frac{-20 \, \text{m}}{4 \text{s}} ~=~ -5 \, \frac{\text m }{ \text s } \]

Since the average velocity is negative, the body moves to the left.

Start position

Unit
Position of the body (on the x-axis) from which the average velocity is to be calculated.

End position

Unit
Position of the body (on the x-axis) up to which the average velocity is to be calculated.

Start time

Unit
The time when the body has the position \(x_1\).

End Time

Unit
The time when the body has the position \(x_2\).