Question

A 20.5 lb cast iron boat anchor displaces 1.33 qt of water when submerged. What is the density of the cast iron, in g/cm3?

1L=1.057 qt
1kg=2.205lb
1lb=453.6g

20.5lb X 453.6g/ 1lb = 9298.9g

1.33qt X 1L/1.057qt = 1.26L

1.26L X 1000cm3/1L = 1260cm3

9298.9g/1260cm3 = 7.38g/cm3

**now why my teacher answer is 7.39g/cm3???

Answer 1

I think you rounded too soon. Just leave those numbers in the calculator.
20.5 x 453.6 = 9298.8 g (slight difference)
1.33 x 1000/1.057 = 1258.3 cc
9298.8/1248.3 = 7.39 g/cc.

Answer 2

thank you so much....your good, I wish you be my teacher I be passing my class with no problem....