# The Difference Between Equation Uniform Acceleration and Average elocity

## Homework Statement

I was just wondering in what instances you would use the two equation belows, and what the difference is between them.

## Homework Equations

average velocity:

vave = Δx/Δt

Uniform Acceleration:

vave = (vi+ vf )/2

## The Attempt at a Solution

I'm assuming that the second equation is just a way of finding the average velocity of time and distance are not known.

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vave?

SammyS
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## Homework Statement

I was just wondering in what instances you would use the two equations below, and what the difference is between them.

## Homework Equations

average velocity:

vave = Δx/Δt

Uniform Acceleration:

vave = (vi+ vf )/2

## The Attempt at a Solution

I'm assuming that the second equation is just a way of finding the average velocity of time and distance are not known.
The first equation, $\displaystyle v_\text{ave}=\frac{\Delta x}{\Delta t}$ is a definition for average velocity, so it's always true.

The second equation, $\displaystyle v_\text{ave}=\frac{v_\text{initial}+v_\text{final}}{2}$ is true for the case of uniform (constant) acceleration. It's not true in general, if the acceleration is not constant.