Too general a question. Need more information.
2 coins come in lots of different sizes and so there cannot be a simple single answer.
Originally coins were different sizes because their values were determined by how much metal they contained. For example, a US dime had roughly 10 cents worth of silver in it, a British sovereign had roughly a pound's worth of gold, etc. People could associate a coin's value with its size, making it easy to tell them apart. Even though circulating coins today don't have any precious metals in them, different sizes still help people to easily distinguish one coin from another without looking at its design or denomination. Having different sizes also facilitates the use of mechanical sorting equipment. Mixed coins are passed through a kind of filter with holes of increasing sizes. The smallest coins drop through the smallest holes first, the next size coins drop through the second set of holes, and so on, and are collected in bins.
You can find one stamped on the coins minted for Panama. They use dollars but call them "Balboas". They actually use coins minted by the US mint in the exact same sizes and denominations as American coins and most denominations of the coins show an image of Balboa on them.
Gold bullion coins are made from precious metals called bullion and minted into coins. These coins are traded on the commodity market and usually come in 1 oz, 1/2 oz, 1/4 oz, 1/10 oz, and 1/20 oz sizes.
At one time coins contained metal that was worth as much as the denomination of the coin, minus a small profit for the government or agency that made the coins. For example, old US cents contained a cent's worth of copper, dimes had 10¢ worth of silver, a quarter-eagle had $2.50 worth of gold, and so on.Because different metals have different values, the coins' sizes were determined by the value of the particular metal they were composed of. That's why, for example, that pennies are larger than dimes - when the penny was copper and the dime was silver, silver was much more valuable so it took less silver to be worth 10 cents than it took copper to be worth 1 cent.However, within each type of coin, sizes were proportional. For instance, a half-dollar was twice the weight of a quarter, and a dollar was 10 times the weight of a dime.When the US took silver out of its coins in the 1960s there was no longer any financial reason to keep coin sizes in proportion, but there were so many vending machines and coin sorters in use that the Mint didn't even consider changing sizes - it would have been too expensive to retrofit all that equipment.However, when new coins are introduced or a country changes its coinage, proportional sizes are generally no longer used except in certain cases. That's why the new US $1 coins are smaller than half-dollars. And in the EU, where all old coins were replaced in 2002, sizes were chosen for convenience and logic rather than proportionality.
Uk gold coins come in various sizes and the value depends on the size.
It depends on what coin you have. Different denominations are different sizes and made of different materials and then have a different melt value.
Coins come in different sizes and weights. You need to specify more clearly a coin. I assume that two coins in the question means a two pence piece? The weight of a two pence piece UK is 7.12g. Therefore: 7.12 x 100 = 712g
Some American Eagle coins include Uncirculated Silver Eagle, Proof Silver Eagle and American Eagle Bullion coins. You can purchase these coins online from the Golden Eagle Coin website or from eBay.
In a vacuum, they will fall together. Air resistance might have a minor affect on the results.
Gold bullion coins are made from precious metals called bullion and minted into coins. These coins are traded on the commodity market and usually come in 1 oz, 1/2 oz, 1/4 oz, 1/10 oz, and 1/20 oz sizes.
That was once the case for coins that were all made from the same type of precious metals but it's no longer true in general. At one time coins in most countries had to contain nearly their face value in some kind of metal. For example, a dime had to contain 10¢ worth of silver, a half-eagle had to be made of $5 worth of gold, and so on. So, for all the coins made of the same type of metal their sizes were in fact proportional to their value simply because they needed to contain proportional amounts of metal. However if two coins were made of different metals, there was no possible way their sizes could be proportional. For example, old US cents had to contain a penny's worth of copper, a metal that's much less valuable than silver. That meant a cent was huge - about the size of a half dollar - compared to a dime even though it's worth only 1/10 as much. As the prices of metals changed and people were willing to accept coins simply because of the denomination struck on them rather than for their intrinsic metal value, it became possible to issue coins whose relative sizes had nothing to do with their relative values. For example pennies were downsized to their current 19 mm diameter in 1857, making them about the same size as dimes. Similarly when nickels were first made in 1866 they were larger than dimes. When the US eliminated silver from its coins during the 1960s there was no metal need to keep the same sizes, but by that time the huge number of vending machines, transit fareboxes, bank coin counters, etc. meant it was easier to keep the traditional sizes than force everyone to retrofit all their equipment. So today the dime and penny have almost the same value of metal in them but people recognize one as being worth a cent and the other as 10 cents. As the Mint gradually introduces new coins they no longer follow the old size rules. Sizes can be chosen for convenience instead of metal value. That's why the "golden" dollar coins are actually smaller than half dollars. Similarly other countries have changed sizes when new coins are introduced. For example the EU has 8 different coins. Instead of increasing in size from 1 cent to 2 euros, they're grouped by color. Coins only increase in size within each color group: > The 1, 2, and 5 cent coins are copper-colored. > The 10, 20, and 50 cent coins are brass-colored. They also increase in size, but the 10 cent piece is smaller than the 5. > The €1 and €2 coins are bi-metallic and the €1 coin is smaller than the 50 cent coin.