# Package time

1. Sep 6, 2006

### marsh

I need some help with a question please.
If a helicopter has a speed of 5.50m/s moving upward vertically and when at the height of 105m above earth a box is dropped from the window how much time will it take to reach the ground?

2. Sep 6, 2006

### daveb

You need to show some work first, and let us know where you are getting stuck.

3. Sep 6, 2006

### marsh

the problem is that i don't know what equation to use for this problem. Would the speed of the helicopter, 5.50m/s, be the speed of the package as well?

4. Sep 6, 2006

### marsh

do i use xf=xi+vit+.5at^2 ?

5. Sep 6, 2006

### HallsofIvy

Staff Emeritus
x= xi+ vit+ (1/2)at2

where xi is the initial height, vi is the initial velocity and a is the acceleration due to gravity. Do you know what the initial height and velocity are for the package?

My answer to your question, which you posted while I was typing, is "yes"!

6. Sep 6, 2006

### marsh

so the xi= om xf=105m and vi=5.50m/s vf= 0m/s a= 9.80m/s^2

7. Sep 6, 2006

### marsh

is that correct?

or is the xf= 0m and xi=105m b/c it's being dropped from the top?

Last edited: Sep 6, 2006