Making it shipshape: Hull designs and hyrodynamics

[NAB]

Hey guys. My first post here. I'm not quite sure how to do the experiment: https://www.sciencebuddies.org/science- ... p019.shtml
The procedure is unclear. Do I make a boat or just a hull? How do I test the drag force?
Thanks.

[NAB]

Correction. I'm supposed to make a boat, but I just don't know how to test it in accordance to this procedure

[kgudger]

Hello and welcome to the forum!

It seems that you've decided to make a boat, but I want to point out that what you're testing is the hull design. If you add anything to the hull (to make it fancy, or to look nice ) you're actually adding variables to the experiment. The procedure says to make each design as close as possible in size. I would also say that you should weigh each design, and aim for them to have the same mass, too, as much as possible. A science fair judge will ask about the mass of each one.

With regards to measuring the drag, the procedure says:

To measure the drag produced by each hull design, place the hull in the rain gutter with the bow end facing towards the hose end. Run a loop of string from the nail or hook on the hull to the spring scale. Hold (or attach) the other end of the scale to the inlet end of the gutter.
For each hull, record the reading on the spring scale. Test all of the hulls at the same flow rate.

I think that describes how to measure the drag. Please get back to us if you have any other questions.
Keith