Chem question.....I tried so many ways and i have one attempt left. Please help!

Question

A copper roof has dimensions of 45.0 feet by 27.5 feet by 0.0216 inches thickness. Copper has a density of 8.96 g / cm³ and a price of 4.17 dollars per pound (as of Jan 12, 2023). What is the cost of copper for this roof in dollars? Report to the correct number of significant figures.

Answer 1

Hello!

This question is focusing on conversion factors.

The final answer asks for the cost, and gives you a conversion for dollars per pound; pound is a unit of mass.

To start with, it gives you length x width x height to calculate volume but gives you different units (feet and inches). You'll want to make sure that everything is the same unit.

It also gives you the density, which is mass over volume. This will allow you to convert from the volume to mass. It gives the density in grams / cm³, so I suggest converting your length/width/height to cm before multiplying them all together (I find this easier than converting cubic feet to cubic centimeter).

Once you've converted from volume to mass (by multiplying the volume times the density) you are left in a mass unit: grams. You'll want to convert this to pounds, since they gave you the price of copper in dollars per pound.

I hope this helps! Please let me know if you have any further questions.