Summer Science Fun: Bowling for Density

For a number of years, I hosted summer science camps, both at our church and at private schools where I taught.  One terrific theme is water, perfect for home-school.  Let's start with density, specifically, The Bowling Ball Experiment.  Will a bowling ball float?  It depends.  Take a large pail or plastic trash can and fill it half-full with water.  Add a big bowl of ice.  The density of ice water is close to 1 g/mL.  A ten pound bowling ball will float and a sixteen pound ball will sink.  A twelve pound bowling ball has a density of approximately 1g/ml and will bob in the ice water bath.  I do this as more of a demonstration with younger kids and walk older kids through the calculations before we test the bowling balls.  Incidently, I bought mine at yard sales.