Register to reply

Calculating Work

by norcal
Tags: work
Share this thread:
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
Experts defend operational earthquake forecasting, counter critiques
EU urged to convert TV frequencies to mobile broadband
Sierra Nevada freshwater runoff could drop 26 percent by 2100
Jun25-07, 07:40 AM
Sci Advisor
HW Helper
P: 25,228
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