- #1
dlacombe13
- 100
- 3
Homework Statement
A fountain shoots water from a fountain that is 3.5cm from the ground. The water reaches a maximum of height of 11cm from the ground (or 7.5cm from the height of the fountain). The range of the water is 15cm from the fountain once it hits the ground. Find:
a) The time the water spends in the air
b) The initial speed of the water
c) The initial angle at which the water is shot
Homework Equations
eq.1) Vxi = Vicos(Θ)
eq.2) Vyi = Visin(Θ)
eq.3) Xf = Xi + Vxit
eq.4) Yf = Yi + 0.5(Vyi + Vyf)t
eq.5) Yf = Yi + Vyit - 0.5gt2
*possibly a few more
The Attempt at a Solution
I have been attempting this one for a while now, with no luck. I suspect it involves a system of equations. I have tried first using equations 4 and 5 to solve for t, but I do not think it gave me the right value for t, since I then tried using t in equation 4 to solve for Vyi, but I also do not think that the value of that is right. I tried from there to use more equations, but the angle ended up being undefined or out of the domain of 0<x<90. I am very lost, any tips for at least where to start would be helpful. My professor did leave some hints:
-Solve for the time to its peak, and then for the time back down, and add them.
-Solve for Viy given the information regarding max. height.
But I still can't figure out where to even begin. All I know is that the y-velocity is 0 at the top, Xf=15, Xi=0, Yf=0, Yi=3.5, range or ΔX = 15, and ΔY = 11