Ok so I know I'm a bad kid, but it's the end of my junior year and i'll feel like such a failure if I can't throw one party, my moms going out of town, i live with my dad, but she locks up the house and has a burglar alarm, I know of and unlocked door and I won't set off the alarm, you don't need to warn me, but i don't know the code, and in the living room there's this weird motion detector and when you walk past it not only does it light up, but so does the main alarm pannel it just holds a solid red light, i'm not planning to trash her house, i love and respect my mommy, i just want to throw a party, will cops come?
Well, I doubt this really should be taken as a hydraulics problem, with nozzle losses, etc. so let's look at it as a conservation of energy problem. At the nozzle, we have a radius Rn and a water velocity Vn. From the radius we can compute the cross-sectional area, and with the area and velocity we can compute the volume of water pumped out every second. volume / time area x length / time area x velocity Taking the density of water to be 1, we can go from volume per second to mass per second and compute the the kinetic energy of the mass. In addition, taking the fire truck as the origin, the water experience a potential energy gain of mgh as it is pumped up to the nozzle. Since we are given h, have computed m, and can assume that we are on the surface of the earth and so use 9.8 m/s^2 for g, we can determine the increase in potential energy per second. Now that we have the potential and kinetic energy gains per second, we can sum them to get the total power required and go back to the fire truck. We know the radius of the hose and the volume of the water pumped per second, so we can compute the velocity of the water in the pump/hose. Then: Power force x velocity (If this isn't clear, consider Work force x distance Power work/time force x distance / time force x velocity) and we know the velocity and the power required, so we can compute the force needed. Force pressure x area and given the radius we can compute the cross-sectional area of the hose. Since we know the force, that gives us the pump pressure.
It's not a federal offense, but you could look at charges at the local level.
