# Projectile motion firehose question

1. Sep 24, 2011

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

In fighting forest fires, airplanes work in support of ground crews by dropping water on the fires. A pilot is practicing by dropping a canister of red dye, hoping to hit a target on the ground below.

if the plane is flying in a horizontal path at an altitude of 86.0 m above the ground and with a speed of 69.0 m/s, at what horizontal distance from the target should the pilot release the canister? Ignore air resistance.

2. Relevant equations

Any constant acceleration equation.

3. The attempt at a solution

ax=0
ay=-9.80

Xo= 0
Yo=86.0

Voy=0
Vox= 69.0

Vx=69.0
Vy=

y=0
x=

I first found Ttotal by using the equation 0-86.0=0+.5(-9.80)(t^2).

t = 4.189 seconds.

then I found Vy.

Vy= 0+(-9.8)(4.189)

Vy= -41.052

Then I realized finding Vy was a complete waste of time. ¯\_(ツ)_/¯

Then I tried to find x.

x-0 = (69.0)(4.189)+.5(-9.8)(4.189)^2

x = 203.05 m/s?

Does this look right?

Last edited: Sep 24, 2011
2. Sep 24, 2011

### bacon

You are right down to where you found T total. In your last equation where you are calculating the value for x, you use an acceleration of -9.8. What is the acceleration along the x axis?(hint, you answered this when you state your value for ax.)

3. Sep 24, 2011