Coin weights

[snopes]

Comment: Is is true that in US currency, a pound of dimes, quarters, and half-dollars in any combination is worth $20?

[mags]

I'm pretty sure a quarter weighs more than 2.5 times a dime, so I'd be exceedingly surprised if this were true.

[Flagg]

http://www.usmint.gov/faqs/circulati...rculating_coin

Here is a link with the weight and metal composition of circulating US coins. Someone who is better at math than me could probably figure out the answer to your question using this chart.

Thinking about your question also reminded me of http://www.coinflation.com which doesn't list the weights of coins, but does show the metal content value of each US coin, both currently circulating and the older silver (pre-1964) coins. Not what you asked, but it does show that every dollar (face amount) in pre-1964 dimes, quarters, or half dollars is currently worth almost $10.00.

It also shows that nickels currently contain about 8 cents worth of metal, and the older pre-1982 cents contain more than 2 cents worth of metal. Gresham's Law, anyone?

ETA: clarification

Originally Posted by Flagg

http://www.usmint.gov/faqs/circulati...rculating_coin

Here is a link with the weight and metal composition of circulating US coins. Someone who is better at math than me could probably figure out the answer to your question using this chart.

$20 worth of dimes = 2000 x 2.268g = 453.6 g = 1 lb
$20 worth of quarters = 80 x 5.670g = 453.6 g
$20 worth of half-dollars = 40 x 11.340g = 453.6 g

i.e. the fact is correct

Originally Posted by forcadragons

$20 worth of dimes = 2000 x 2.268g = 453.6 g = 1 lb

$20 worth of dimes is actually 200 dimes, not 2000. 200 dimes makes your equation work, 2000 dimes would be 10 lbs.

[Don Enrico]

Originally Posted by forcadragons

$20 worth of dimes = 200 x 2.268g = 453.6 g = 1 lb
$20 worth of quarters = 80 x 5.670g = 453.6 g
$20 worth of half-dollars = 40 x 11.340g = 453.6 g

i.e. the fact is correct

[quote changed because of typo]

What about mixed combinations?

It works for

100 dimes (226.8g) + 20 quarters (113.4g) + 10 half-dollars (113.4g) = $20 (453.6g)

but does it work for all possible combinations?

Done Enrico

It will work for all combinations of dimes, quarters and half-dollars, since they are all worth $1 per 22.68g

Originally Posted by nevermore.1971

$20 worth of dimes is actually 200 dimes, not 2000. 200 dimes makes your equation work, 2000 dimes would be 10 lbs.

Caught by the pedantry police after almost two months!

[Hans Off]

Originally Posted by forcadragons

Caught by the pedantry police after almost two months!

Call me a pedant, but correcting a mathematical error of that magintude goes beyond pedantry!

Originally Posted by Hans Off

Call me a pedant, but correcting a mathematical error of that magintude goes beyond pedantry!

OK, but you knew what I meant. And I knew what I meant (honestly). I'm not as bad as Verizon.

[Alchemy]

Just divide the weight of each coin by the face value and figure out if the weight per cent is equivalent.

Penny
2.500 g/cent
Nickel
1.000 g/cent
Dime
0.2268 g/cent
Quarter
0.2268 g/cent
Half dollar
0.2268 g/cent
Dollar
0.081 g/cent

So any collection of dimes, quarters, and half-dollars will have a value of 4.409 cents per gram.

Doesn't work with pennies, nickels, and dollars.

[RivkahChaya]

It works, because back when dimes, quarters, half-dollars, and dollar coins were all silver, they contained their respective face values of silver, so a quarter would weigh 2.5 x what a dime did. The nickel-copper et al. coins in circulation now weigh almost the same as the silver originals. Dollars changed in size back in 1979, when the Susan B. Anthony dollar came out, but I'm sure this weight = value formula would work if you used the non-silver, but silver dollar sized, Eisenhower dollars from the 1970s.

Once upon a time, cents and 5-cent nickel pieces (there was also a 3-cent nickel once, in the 1860s) contained their face value in metal, but no longer. Cents haven't been all copper for about 150 years, and since the early 80s, have been a bronze plate over zinc. Cut one in half; they're white inside.

FWIW, there are minute weight differences between silver, and copper-nickel coins, but you have to have more than $10 in coins before the difference shows up on an ordinary household scale.