6. A block of wood floats in freshwater with two-thirds of its volume submerged. In oil the block
floats with 0.90 of its volume submerged. Find the density of the wood and the oil.
7. An iron anchor of density 7870 kg/m3
appears 200 N lighter in water than in air. What is the
volume of the anchor? How much does it weigh in air?