# Helicopter problem

1. Sep 30, 2014

### Turntbull

1. A helicopter starts from rest on the ground and starts accelerating uniformly upward. After 30 seconds a flare was fired horizontally. An observer on the ground measured the time the flare reaches the ground to be 10 seconds calculate A) acceleration of helicopter B) hight flare was fired C) the height of the helicopter the instant the flare reaches the ground assuming the acceleration stays constant

2. Voy = Vo sin theta
The constant acceleration equations

3. I don't know where to start to find acceleration. I have done sin90 to try and get voy but I know that's wrong cuz my teacher said I'm doing it all wrong lol plz help

2. Sep 30, 2014

### Staff: Mentor

Hi Turntbull.

Can you find an expression for the time the flare takes to reach the ground after its release?

3. Oct 1, 2014

### PeterO

Because the flare was fired horizontally, the time involved is the same as if an object was dropped - by dropped I mean held in an outstretched hand and released - it does not necessarily travel down immediately.