A wooden plank 2 m long, 30 cm wide, and 40 mm thick floats in water with 10 mm of its thickness above the surface. What is the mass of the board? The answer is 18 kg
I am trying to figure out how they got that answer.
I know that d = m/v and in order to get mass you use m = d(v). Where does the 10 mm come into play. Also the denisty of water is 1.00 x 103 ... do I use that? I keep getting a ridiculous answer. Any help would be highly appreciated!