Calculating Average Acceleration in an Acceleration Test

[CraZyFanAtiC]

Hey, guys just joined PF, was hoping you could help with this questions and in turn maybe i can return the favour (with the little physics knowledge I have).

Homework Statement

In a acceleration test, 2 markers are placed 0.30 km apart. The first car passed the first marked with a velocity of 5.0 m/s [E], the second passed the marker with a velocity of 33.0 m/s [E]. Calculate the Cars average acceleration.

Homework Equations

v1 = 5.0 m/s [E]
v2 = 33 m/s [E]
Delta D = 0.30 km
Aav = ?

The kinematics that i am using is Vf² = Vi² + 2aav(d)

The Attempt at a Solution

The problem i am having is rewriting the equation.
I need to rewrite this for aav.

Vf² - Vi² = Vi² + 2aav(d)

vf² - vi²/2(d) = aav

This is what i have so far, but it must be wrong i just don't see how. When i plug in the numbers..

1089 - 25/2(0.3) = aav
1064/0.6 = aav
aav = 1773.3

this can't be right can anyone help me?

 

[rl.bhat]

Hi CraZyFanAtic, welcome to PF.
Convert the distance from kilometer to meter.

 

[CraZyFanAtiC]

Hi CraZyFanAtic, welcome to PF.
Convert the distance from kilometer to meter.

O, wow do i feel stupid. First time I've seen a question like that just didn't think about it, thanks a lot. Saved me a lot of time.