# Free fall motion from airplane

1. Sep 14, 2012

### bdh2991

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

A package is dropped at time t = 0 from a helicopter that is ascending steadily at a speed vi.
What is the speed of the package in terms of V$_{i}$, g, and t?

2. Relevant equations

V (t) = V$_{o}$ + -9.8 t

3. The attempt at a solution

I thought it was the same as the normal equation for velocity such as stated above but with the different variables substituted for example:

|V| = V$_{i}$ + gt

except i got the answer wrong, then i tried putting a negative sign on the v$_{i}$ part but still got it wrong...help would be greatly appreciated.

2. Sep 14, 2012

### lewando

You are close. Speed is |v(t)|. Try putting the magnitude bars around your expression for v(t).

3. Sep 14, 2012

### bdh2991

the magnitude bars are already there on the online hw, only the stuff to the right of the "=" sign is what i'm able to input....

nvm i see what your saying....but there was another part of the question in which the plane was descending and asked the same question and i got it right without putting the '|' around v(t)

Last edited: Sep 14, 2012
4. Sep 15, 2012

### CWatters

Try

|V| = |Vi - gt|

or

|V| = |gt - Vi|

5. Sep 15, 2012

### bdh2991

tried both but neither worked...i really think it is just the stupid website that i have to do the hw on but i'm all out of chances so doesn't matter now lol thanks for the suggestions though

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