Help needed with converting units?

Question

I'm totally confusing with this chem homework...I'm not mooching either, i just have no clue how to do this...

Note when you see "3" it would be in superscript if it could...

As an astute observer walking around on continental crust (granite), you might decide to test the hypothesis that the Earth is made entirely of granite. You weight a 1.00 cubic ft. piece of granite on your home scale and find that it weighs 171 lbs. Thus you determine that the granite has a density of 171 lb/ft. Convert your granite's density to g/cm3. Given the information above, could the earth be completely made of granite?

Thanks!

Answer 1

To show superscripts just use SHIFT + 6 and then your number (power). Note this is different than your number times 10^3.

1 lb. = 453. 59237 g. according to google.com since we are using two different systems this is easier than converting. (453.59237 g)(171 lb./ft^3) = 77564.29527 g/ft^3. Now, 1 gram/ft^3 = 3.53146667 x 10^-5 grams/cm^3. (3.53146667 x 10^-5 grams/cm^3)(77564.29527 g/ft^3) = 2.74 g/cm^3. Looking at 5.5 g/cm^3, the earth could not be completely made of granite.

    

Answer 2

Follow the instructions as given in my answer to your other question. It's the same principle each time.