A tank has the shape of an inverted circular cone (point at the bottom) with height 10 feet and radius 4 feet. The tank is full of water. We pump out water (to a pipe at the top of the tank) until the water level is 5 feet from the bottom. The work W required to do this is given by? I have nowhere left to turn :/ NO SHAME
Ooh fun, this thread is for me! Future math and physics teacher here to help. Well, my teacher instinct is telling me not to just give it away, so let me aim you in the right direction with another question (aren't teachers just awesome?)
What's the potential energy of the water you wish to displace?
PM me if you still need help.
Last edited by NuneShelping; 09-08-2010 at 11:54 PM.
Oh god I'll probably have problems like this in 2 weeks time...
I thought work only applied to upwards force? My last physics class jumped ship and pushing a 10 pound weight up a 45 degree slope lol. I would suggest using calculus to make some shortcut by integrating the inverse formula of the inverse of... I dunno haha
This is a very similar problem. you will merely need to change the numbers, remove the extra 5ft that is h2, and account for only pumping the top 5 ft.
Hope it ain't to late :P
-this is not my work.
W = (Force)*(distance)
W = (mass)*(acceleration)*(distance)
//h is the height of the slice -it is the variable
//r = 2/5h (relationship of cone height to radius) - this allows us to use only one variable, h
//1000kg/m^3 is the density of water. This multiplied by the volume will give the total mass
//dh is the change in height
Fill in all the numbers, convert to SI units, simplify, integrate from 1.524m(5ft)-3.048m(10ft)