Word problem-I would like to check my procedure

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Homework Help Overview

The discussion revolves around a word problem involving a cubical ice block melting at a rate related to its surface area. Participants are tasked with setting up an equation for the volume of the cube in terms of its surface area.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to relate the volume and surface area of a cube using calculus, expressing the volume and surface area in terms of the side length. They question the next steps after deriving a relationship between the rates of change.
  • Some participants suggest focusing on the surface area to derive a formula for the side length, indicating a shift away from a calculus approach.
  • There is a request for clarification on how to proceed with the problem, reflecting uncertainty in interpreting the requirements.

Discussion Status

Participants are engaged in clarifying the problem's requirements and exploring different approaches to relate the volume and surface area. Some guidance has been offered regarding the need to manipulate the surface area equation to find the side length, but no consensus has been reached on the final approach.

Contextual Notes

The original poster expresses difficulty with interpreting word problems and seeks more specific guidance, indicating a potential gap in understanding the problem's setup.

stanton
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word problem-Please help me to check my procedure

Homework Statement



A cubical ice block is melting at a rate that relates to its surface area. Set up an equation for the volume of a cube, C, in terms of its surface area, S.

Homework Equations



C=x^3
S=6x^2

The Attempt at a Solution




let length of the side of the cube:x
dC/dx=3x^2 dS/dx=12x dC/dS=x/4
Now what should I do? I think I did pretty well until now. How should I use this information for getting the answer? Or dC/dS(which is x/4) is the final answer?
 
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You are almost half-way there, and this is not a calculus problem.

Work with S and find a formula for x.
 
Thank you. But work with S? Would you mind if I want more specific explanation from you? Sorry, cause I am not very good at math, interpreting word problems.
 
The problem said "Set up an equation for the volume of a cube, C, in terms of its surface area, S". That's why you need to "work with S".
You have [itex]C= x^3[/itex]. You also know that [/itex]S= 6x^2[/itex].

Solve [itex]S= 6x^2[/itex] for x (which is a length and so positive) and replace the "x" in [itex]C= x^3[/itex] with that/
 

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