Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] density

On 10/06/2008 10:42 AM, Anthony Lapinski wrote:
I want to do a density activity by filling empty soda cans with washers to
make them less buoyant. Is there a low mass "foam" available (Home Depot?)
that can be sprayed into the cams to seal the weights on the bottom so
that no water can get inside?


It comes in a spray can. For a few bucks you get enough foam to
fill at least 100 soda cans. As it says in the instructions, the
foam expands a lot after it is dispensed. The expansion is not
immediate, so don't succumb to the temptation to apply too much.

Using "washers" seems unnecessarily costly. Why not just use sand?

If you ever really need metal weights, stop by the hardware aisle
at Home Despot and collect some of the ruined links that are produced
every time they cut a length of chain. Those are free. (I ask
permission each time, but the answer is always "free".)