Calculating Work


by norcal
Tags: work
norcal
norcal is offline
#1
Jun24-07, 10:59 PM
P: 19
1. The problem statement, all variables and given/known data

The hemispherical tank shown is full of water. Given that water weighs 62.5 lb/ft3, find the work required to pump the water out of the tank. (the water will be pumped out of a spigot at the top)

2. Relevant equations

INTEGRAL from 0 to 5 of: pi*(5-h)(25-h^2)dh

3. The attempt at a solution

INTEGRAL from 0 to 5 of: pi*(h^3-5h^2-25h+125)dh

pi*((h^4)/4 - (5h^3)/3 - 12.5h^2 + 125h)

= (3125/12)*pi ft-lb.

This answer is incorrect though...anyone know what I am doing wrong? Thanks.
Phys.Org News Partner Science news on Phys.org
Cougars' diverse diet helped them survive the Pleistocene mass extinction
Cyber risks can cause disruption on scale of 2008 crisis, study says
Mantis shrimp stronger than airplanes
Dick
Dick is offline
#2
Jun25-07, 07:40 AM
Sci Advisor
HW Helper
Thanks
P: 25,173
You didn't use the density of water data. How would you incorporate this?


Register to reply

Related Discussions
Calculating Work Calculus 0
calculating work done by friction Introductory Physics Homework 3
Calculating Work Advanced Physics Homework 3
Calculating the work done by friction Introductory Physics Homework 11
Calculating Net Work Introductory Physics Homework 3