# Find Acceleration Experimentally

1. Oct 8, 2009

### Power of One

You drop an object. You take the time it takes to hit the ground. So you have Δx (displacement) and time.

To find acceleration do you use

xf= xi + Vi t + .5at2
Δ x= Vi t + .5at2
Δ x- Vi t=.5at2
a= 2(Δ x- Vit )/ t2

or do you use

v= Δ x/ Δ t
a= Δ v/ Δ t

Should acceleration come out the same? Why do they differ so much? Take example a Δx of 2m and a time of .5. Using the first equation you get 16 m/s^2. But using the second method, you get 8 m/s^2.

2. Oct 8, 2009

### Vykan12

It seems to me that you're not given enough information. If you had the initial and final velocity, you could plug into

$$V_{f} = V_{i} + at$$

to experimentally find the acceleration.

What would be easier is to use newton's second law (F=ma) since then you only need to know the object's mass and the force it exerts on the ground upon impact to experimentally determine the value of g.