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