My answer doesn't make sense. I will show question then my work: A city holding tank for water sits 20 m above the city. If a house was on fire 15 m
away from the base of the holding tank, and the tank was originally filled to a depth of
15 m, to what depth would firefighters have to drain the tank so water, sprayed from
the bottom of the tank, hits the bottom of the house?
step1: Viy=0, a=g=9.8m/s/s, dy=20
dy=Viyt + 1/2 at^2 -->
t = sqrt(40m/9.8m/s/s)= 2.02s
Step2: Vx=dx/t and Vx=15m/2.02s=7.43m/s
Step 3: change in x = 15m (distance house from water tower) and change in h (depth of water) = 15m
change in X = Vx(sqrt(2h/g) or
h = [(x^2)(g)]/[(Vx^2)(2)]
h = ((15^2)(9.8)]/[(7.43^2)(2)] m
h= 19.97m
That's more meters than I have. Not sure what I missed.
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