19 October 2005

3rd grade physics

Jakob's homework today was to show an adult (or more) a 'trick' from physics class this morning. And make us guess the result.

Here's how: Place a glass on a piece of paper. Then you fill it to the brim with water. And I mean to the brim! Then slowly 'insert' coins like this into the water, sideways (thin side down) into the glass. (This one's Danish, but never mind!)

How many coins can you put in before it spills?

I can say this much: I guessed 1, then 5 when laughed at... My hubby guessed 2. We were both wrong... Anyone?

I don't know that we even did physics at the age of 7 in my time...

Update: I'll post the answer in a comment, in case anyone else wishes to wager a guess. Wait, that won't work, will it? I'll post the answer under the comments of the previous post, then ;)


Rarity said...

Ehrrr... I'll guess three, cause as we say over here:"All god things are three" (sunds weird in English, for some reason)

Sam said...

All good things come in threes.

I say 4.

"D" said...

I'll opt for 7...I understand putting them in sideways, and I know you can probably fit a good deal in there before the surface tension breaks at the lip of the cup, but as to exactly how many? Can't wait to hear!

Rocket Scientist Brainiac said...

Does it work with euros as well?

Claire said...

Hmm. I'm torn between surface tension and water displacement as arguments, but I'll say none.