I need help with a physics lab project...

stevey500 · 08-25-05, 05:33 PM

Okay, tomorrow we have a weird lab we have to do... here is what it is

We are given 26 film canisters... the little black ones with the grey cap labeled A-Z... each of them have a random ammount of pennies in them, we are supposed to find out how many penny's are in each canister without opening them... the only tool given is the balance. I kinda have this figured out, and thought it would be easiest if I could just find a canister and weigh one now and use that to calculate how many penny's are in each canister... out of the 26 canisters there is one that only has one penny, thats the one I'll have to weigh to find the weight of a penny. Unfortunately I dont have a film canister around here anywhere... could anyone help me out... or give some suggestions, anything at all will help

THanks! Our science teacher is no help haha..

thanks

Howard2k · 08-25-05, 05:35 PM

I think I know the answer to this, but keep coming up with suggestions. I think you're almost there

**Martin** · 08-25-05, 05:38 PM

Quote:

Originally Posted by Howard2k

I think I know the answer to this, but keep coming up with suggestions. I think you're almost there

You should be a teacher, Howard! Pretending to know the answer so you push the student further, and you look omniscient at the end! Brilliant...

Howard2k · 08-25-05, 05:52 PM

Either that or lawyer. Same practices would apply wouldn't they?

rsaturn9 · 08-25-05, 05:58 PM

wow that sounds like a fun lab to me!!

darkdestroyer · 08-25-05, 05:58 PM

Thats an easy lab. If you are timed, then i have absolutly no clue. But otherwise.

Solution 1
If the number of pennies in the 26 canisters are 1,2,3,4,5...26. (Every number from 1-26 is included and is only used once)Then measure them all and plug in the numbers (Too easy....Hmmm)

Solution 2
Totally Random Number of Pennies
Measure them out, Find the 2 that are the closest in weight. Subtract the heavier one to the lighter one, Bing!!! The weight of the Penny

Solution 3
CHEAT
Measure out a penny now. A canister would probably count as the weight of 2 pennys, 3 if you have the cap on.

stevey500 · 08-25-05, 06:32 PM

Quote:

Originally Posted by darkdestroyer

Thats an easy lab. If you are timed, then i have absolutly no clue. But otherwise.

Solution 1
If the number of pennies in the 26 canisters are 1,2,3,4,5...26. (Every number from 1-26 is included and is only used once)Then measure them all and plug in the numbers (Too easy....Hmmm)

Solution 2
Totally Random Number of Pennies
Measure them out, Find the 2 that are the closest in weight. Subtract the heavier one to the lighter one, Bing!!! The weight of the Penny

Solution 3
CHEAT
Measure out a penny now. A canister would probably count as the weight of 2 pennys, 3 if you have the cap on.

wow... solution 2 sounds like the one to me. solution 3 could be possible, hah he just said do whatever it takes to get the answer, except for copying off your friends lol. But yeah I might have ended up thinking of that after recording the data... but not before lol. thankS!

**Martin** · 08-25-05, 07:00 PM

Quote:

Originally Posted by Howard2k

Either that or lawyer. Same practices would apply wouldn't they?

Cheeky sod.

For that, Howard, I'm going to do something deeply embarrassing to you...

darkdestroyer · 08-25-05, 07:01 PM

My Oh My!!

**Martin** · 08-25-05, 07:15 PM

In fact...

Howard2k · 08-25-05, 08:06 PM

Now we both know that no-one REALLY loves Arse

Ken S · 08-25-05, 09:11 PM

I hope the teacher used either new or old pennies, I forget exactly when, but sometime in the eighties when the price of copper soared the government changed pennies from being solid copper to a copper clad zinc. Since no vending machines accept pennies no effort was made to keep the weight the same so newer pennies are noticably lighter than old pennies.