Help Help Help Fluid problem

[Dragoon]

this is what the problem states i need help getting going
An ameusement park is planning to build a water slid, and the park owners would like to use giants corcks (pc=.28 g/cm3) as floats for young children. what volumer of cork is needed to keep 20 percent by volume of 40 kg child above the water at the base of the water slide (assuming the density of a child is 1.01 g/cm3.

[marlon]

well what do you have up till now. Maybe some hints : there are a few ways to solve this one. Think of stuff like pressure and the relation between pressure-difference and height difference : p = p' + ro*g*(h'-h)... where ro is the density of the surrounding matter. Also consider Archimedes' law...

Please do not cross-post...

regards
marlon