# Kinematics, given only vi vf and d

1. Oct 4, 2008

### Omnistegan

Kinematics, given only "vi" "vf" and "d"

1. The problem statement, all variables and given/known data

I have a hunch this problem is impossible with the given information.

Using the given information, solve for a and t.

vi = 7.185m/s
vf = -7.185m/s
a = ?
d = 0m
t = ?

2. Relevant equations

Not sure, I think this would be correct.

vf^2 = vi^2 + 2ad (The problem here is obvious when d = 0)
d = 1/2(vi+vf)t (Once again, as far as I can tell, useless when d = 0)

3. The attempt at a solution

Well I can plug and chug the numbers the same as anyone, the problem is that it will always come out to zero.

Thanks in advance guys.

Last edited: Oct 4, 2008
2. Oct 4, 2008

### gabbagabbahey

Re: Kinematics, given only "vi" "vf" and "d"

Are you sure d=0? What is the original problem statement, word for word?

3. Oct 4, 2008

### Omnistegan

Re: Kinematics, given only "vi" "vf" and "d"

d certainly is 0.
The question is exactly as I have above.
My impression was that this question resembled the vertical component of a projectile motion question. Up and back down, 0 displacement.

4. Oct 4, 2008

### Rake-MC

Re: Kinematics, given only "vi" "vf" and "d"

My opinion is that it can't be solved with only that information. Perhaps we're thinking too hard though

5. Oct 4, 2008

### Varnick

Re: Kinematics, given only "vi" "vf" and "d"

It would seem to me that the question has been misinterpreted, or miswritten. I certainly don't see a way to solve it with the current data.