Related Rates: Calculating Height and Radius of a Conical Pile

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Homework Help Overview

The problem involves related rates concerning a conical pile of sand, where the height is a function of the base diameter. Participants are exploring how the height and radius of the pile change over time as sand is added at a constant volume rate.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between the volume of a cone and its dimensions, questioning how to express the volume in terms of the radius and height. There is an attempt to clarify the implications of the given rate of volume change.

Discussion Status

Some participants have provided hints regarding the volume formula for a cone and its relation to the rates of change of height and radius. The discussion appears to be progressing with attempts to establish the necessary equations for further analysis.

Contextual Notes

The original poster expresses uncertainty about how to initiate their solution. There is a specific focus on the relationship between height and radius, which is defined in the problem statement.

Willowz
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Homework Statement


Sand falls from a conveyor belt at the rate of 10 m^3/min onto the top of a conical pile. The height of the pile is always three-eighths of the base diameter. How fast are the a) height and b) radius changing when the pile is 4m high?


Homework Equations


h = 3/8 * 2r


The Attempt at a Solution


I'm not sure where to start. I just need a small hint.
 
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The question is giving you dV/dt. What's the equation for the volume of a cone in terms of r and h? That's a small hint.
 
More than enough. Thanks
 
The rate of change of the volume of the cone is 10 m3 per minute. What is the expression for the volume of a cone in terms of its height and base radius? This will allow you determine dr/t or dh/t in terms of dV/dt.

EDIT: two minutes too late...
 

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