MATLAB Answers

Suman Koirala

This is a minimisation problem where I get input from the user for W, lb and lc. And find the minimum value of T for minimum of D. T is given by the relationship as seen in the program. I keep on getting error on that. Thanks for any help.

Asked by Suman Koirala
on 20 Feb 2013

L c



L b

Problem: A cable of length L c supports a beam of length L b so that it is horizontal when 
the weight W is attached to the beam end. The tension force T in the cable is given by the 
following equation: 
T 
L bL c W 
D L 2D 2 
Where D is the distance of the cable attachment point to the beam pivot. 
Create an M-file that: 
a) Prompts for and accepts the following inputs from the Command Window : W, L b, and 
L c (the weight is in Newtons, and the lengths are in meters), then uses these values to 
compute and display in the Command Window the value of D that minimizes the 
tension, T , (do not use a loop in your M-file to perform this computation). 
b) Your M-file should also display the minimum tension value in the Command Window, 
and produce a well annotated graph of T versus D. 
c) Lastly, explain in a comment section at the bottom of your M-file how much the value 
of D can vary from it’s optimal value before the tension increases by more than 10% 
from it’s minimum. 



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1 Answer

Answer by Alan Weiss
on 20 Feb 2013

This sounds like a transcription of a homework problem. We generally don't like to simply solve people's homework for them.

If you want help, show people what you have done, and where your program throws an error.

Alan Weiss

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