- #1

rocketlaunch

- 3

- 0

## Homework Statement

Find the initial velocity of the boost phase (when water is coming out). Here is everything I know -

- Mass of rocket with no water is 0.13kg, mass of rocket with water is 1.1kg. The total length of the rocket is 0.48m.
- The time to the maximum point is 3.46 seconds, and total time of flight is 6.68 seconds. The duration of the boost phase is 0.4 seconds.
- The height reached at the end of the boost phase is 21.9m.

## Homework Equations

The kinematics equations.

## The Attempt at a Solution

I am aware that one of the kinematics equations must be used, however, at the end of the boost phase, final velocity is not zero, and I don't know the acceleration (I would say 9.8m/s^2, but doesn't that change?). With 2 variables missing, I don't see how I can solve for initial velocity. Knowing displacement and time, how can I figure this out? [/B]