# Homework Help: Density & Integration... Help?

1. Mar 18, 2017

### sunnnystrong

1. The problem statement, all variables and given/known data

A hole in the ground in the shape of an inverted cone is 19 meters deep and has radius at the top of 16 meters. The cone is filled to the top with sawdust. The density of the sawdust depends upon the depth, x, following the formula ρ(x) = 2.1 + 1.2e^(-1.2x) kg/m^3. Find the total mass of sawdust in the conical hole.

2. Relevant equations

mass = density * volume

3. The attempt at a solution

So I'm just confused as to how to set up my integral?

I want to find the def. ∫ density*volume from 0 to 9

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2. Mar 18, 2017

### sunnnystrong

Using the relationship I posted above ^^^

radius of cone = 16m
height of cone = 19m
s = (16/19)(19-x)
So my integral would be....

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3. Mar 18, 2017

### sunnnystrong

Anyone? D:

4. Mar 19, 2017

### sunnnystrong

*** Figured it out. all you had to do was square the constant (16/19) as well.

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