# Finding the acceleration when initial velocity is not known.

## Homework Statement

In 2.0 s, a particle moving with constant acceleration along the x axis goes from x = 10 m to x = 50 m. The velocity at the end of this time interval is 10 m/s. What is the acceleration of the particle?

## Homework Equations

kinematic equations

## The Attempt at a Solution

i'm quite sure its an deceleration because if i calculate the average speed over the period of time i get 40/2 = 20ms-1, which is faster than the final velocity. I haven't find the way to calculate acceleration without initial velocity since every kinematic formula i know have Vi.

Thanks

## The Attempt at a Solution

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i'm quite sure its an deceleration because if i calculate the average speed over the period of time i get 40/2 = 20ms-1, which is faster than the final velocity.
Good. That means the acceleration is negative.
I haven't find the way to calculate acceleration without initial velocity since every kinematic formula i know have Vi.
Since you calculated the average velocity, use it to figure out the initial velocity.

!@&(^#

Thank you..silly me. (i actually went all the way to solve it graphwise...)