Science and an explanation

[gstours]

Another reason I should have paid attention in school has to do with the simplest things.
   Recently I wanted to find the approximate weight of a lead jig by using the water displacement idea for the pattern/master.   To my consternation after filling the test cylinder with water slowly thee water just kept rising up and did not run/fall out the notch shown below until it was quite a bit higher than the notch.
   This caused my calculations to vary.   And was not satisfied.

[gstours]

Lacking a graduated cylinder my thoughts were to weigh the water before and after the object was placed in the water.   Finally a line was placed on the side of the cylinder for the water height.
  This seems to help aiding in accuracy.
       What is the reasoning of my findings.   Thanks for your thoughts .   

[Dominick]

All you had to do was break the surface tension at the notch.  I wasn't playing hooky the day they taught surface tension.     Dominick

[Jimmer]

A drop or two of dish soap will break the surface tension.

[Keta]

A drop or two of dish soap will break the surface tension.

Yup.

[jurelometer]

Might be easier/more accurate to do it this way:

1.  Fill the beaker part way.

2. Submerge the model.

3.  Mark a line at  the new water level.  Remove model.

4. place the beaker with water on your scale and tare to zero.

5.  Add water to the new line.  Record the new weight.

6.  Multiply new weight by 11.3 (the density ratio of lead to water).  

All you had to do was break the surface tension at the notch.  I wasn't playing hooky the day they taught surface tension.    Dominick

A bit more explanation:  Water molecules are strongly attracted to each other due to the hydrogen bonds, which are particularly strong compared to most of the stuff around it.  That is why a rain drop holds together while falling through the sky.  A water molecule in the center of the beaker  is clinging to other water molecules on all sides.  The molecules on the surface have no water above, so they can cling more strongly to other surface molecules.  This makes a tight skin of water that is trying to shrink, pulling the edges in and causing a dome shaped surface.  Or something like that.  Like Dominic, I was in class that day, but I was starting to nod off...

The intermolecular attraction of water is some pretty cool stuff.  I read somewhere that if a person was the size of a microorganism, moving through water would be like crawling through a thick gel.  But if you were a large as a blue whale, moving through water would feel like swimming through air.   Yet another reason to help yourself to another slice of that apple pie

-J

[Wompus Cat]

Since you already have the Mold why not just make a jig and weigh the jig unless I mis -interpolate the scenario here.
I mean you are displacing an indeterminate amount with the shape and volume of cavity of the mold when you put the mold in the measure .
This type of measurement works well in cooking recipes like when you want measure an amount of butter with out the dish in there too .
I don't understand anyway . but my finger tips were itching so I figured I would type in here a bit .

[Benni3]

I'm not that smart,,,,, but I would try it at water temperature at 28 degrees and ad salt,,,,,,,,

[gstours]

Thanks everyone for chiming in. .  You were right on about the surface tension.  Its seemingly even in the news everytime i grab the remote.
   Now if,n I,d just stayed awake in class?    I wouldnt have to bother you all.
Butt seriously this Alans Place is great.  Learning is Living for me.....
  I sorta remembered the surface tension reasoning, and did sorta what Dave suggested eventually by making a line, adding the part, and  remarking a second line, removing the part, then trying to calculate the difference with a gram scale...  Now I know.   many thanks.