**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?

The correct answer for A flat slab of styrofoam, with a density of 32 kg/m^3, floats on a lake.

bouyancy-42g=0

density water*g*volume-32g*volume-42g=0

volume= 42/(densitywater-32kg/m^3)

density water = 1000kg/m^3 approx.