Question

a block of metal which weighs 60 newtons in air and 40 newtons under water has a density, in kilograms per meter cubed, of:

Answer 1

B = buoyant force of water = (60 - 40) N = 20 N

S (specific gravity) = Weight object / Weight of water

S (water) = 1 gm/cc = 1000 kg/m^3

S (block) = 60 N / 20 N * 1000 kg/m^3 = 3000 kg/m^3