A flat slab of styrofoam, with a density of 32 kg/m^3, floats on a lake. What is the minimum volume the slab must have so that a 42 kg boy can sit on the slab without it sinking?

3 answers

bouyancy-42g=0

density water*g*volume-32g*volume-42g=0
volume= 42/(densitywater-32kg/m^3)

density water = 1000kg/m^3 about.
i have the same question, and i got .043 m^3. but it's not the right answer. what did i do wrong? ( i use the same formula too.)
nvm. i submit the answer wrong.