User Name Remember Me? Password

 Calculus Calculus Math Forum

 February 1st, 2015, 12:31 AM #11 Member   Joined: Dec 2014 From: Queensland Posts: 59 Thanks: 2 the course im in is an itroductory course to engineering mathmatics. I havent been informed of the consant k of proportionality. My question was You are to mill a beam from a cylindrical wooden log. The strength S of a beam is proportional to its width (w) and to the square of its depth (d). What is the width and depth of the strongest beam that can be cut from a 300 mm diameter wooden log? from this i get $$S=wd^{2}$$ and the $$w=300^{2}-w^{2}$$ was also $$w=\sqrt{90000}-\sqrt{30000}$$ $$S$$ is proportional to $$wd^{2}$$ is it not from the statement? meaning $$S=wd^{2}$$. can $$k$$ be $$1$$? so am i wrong? we havent been tought the constant of proprotionality as i thought s was proportional to w*d^2. am i wrong? Last edited by unistu; February 1st, 2015 at 01:05 AM. February 1st, 2015, 09:56 AM   #12
Global Moderator

Joined: Nov 2006
From: UTC -5

Posts: 16,046
Thanks: 938

Math Focus: Number theory, computational mathematics, combinatorics, FOM, symbolic logic, TCS, algorithms
Quote:
 Originally Posted by unistu the course im in is an itroductory course to engineering mathmatics. I havent been informed of the consant k of proportionality. My question was You are to mill a beam from a cylindrical wooden log. The strength S of a beam is proportional to its width (w) and to the square of its depth (d). What is the width and depth of the strongest beam that can be cut from a 300 mm diameter wooden log? from this i get $$S=wd^{2}$$
Not quite -- it's S = kwd^2 for some constant k. It will turn out that it doesn't matter what k is, though, so you'd get the same answer then if you assumed k = 1. Tags finding, maximum, size Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Similar Threads Thread Thread Starter Forum Replies Last Post BenFRayfield Applied Math 4 December 21st, 2013 10:58 PM ungeheuer Calculus 13 August 24th, 2013 11:34 AM sachinrajsharma Algebra 10 February 12th, 2013 08:23 PM winnerhere Algebra 3 August 11th, 2010 09:07 AM Red5 Calculus 2 July 25th, 2010 10:54 AM

 Contact - Home - Forums - Cryptocurrency Forum - Top

Copyright © 2019 My Math Forum. All rights reserved.      