Horizontal distance: 35=Vcos35*t
vertical ditance: hf=ho+Vsin35*t-1/2 g t^2
solve for t in the first equation: t= 35/VCos35=42.7/V put it in for t in the second equation:
0=4.5+Vsin35(42.7/V)-4.9(42.7/V)^2
multiply thru by V^2, and you have a quadratic. Use the quadratic formula to slove for V
A brush fire is burning on a rock ledge on one side of a ravine that is 35 m wide. A fire truck sits on the opposite side of the ravine at an elevation 4.5 m above the burning brush. The fire hose nozzle is aimed 35∘ above horizontal, and the firefighters control the water velocity by adjusting the water pressure. Because the water supply at a wilderness fire is limited, the firefighters want to use as little as possible.
Part A
At what speed should the stream of water leave the hose so that the water hits the fire on the first shot?
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2 answers