Usually you would weigh it, on a device that is calibrated to show mass.
To find out the density of a coin, you would first measure its mass using a scale, and then measure its volume using displacement method or by calculating the volume based on its dimensions. The density of the coin can be calculated by dividing the mass by the volume.
its mass will increase by an amount too small to measure directly
The mass of any coin is typically measured in grams; the capacity or volume would be measured in millilitres.
Only if the items being measured are all identical. Otherwise you will lose the variation between individual items. It would be sensible to measure the mass of ten identical coins and take their average as a measure of the mass of a coin. But the average mass of ten people is not a more accurate measure of any of their masses.
Drop 10 coins of the same size and mass into a container filled with water, making sure that the water that overflows from the container is collected. Now measure the volume of the water overflow an multiply it with the density of water which is 1 kg/l. Now divide the total mass by 10 to get the mass of one coin.
The mass of a copper coin can vary depending on the size and denomination of the coin. On average, a copper coin like a US penny weighs about 2.5 grams.
Mass is the measure of matter in an objevt
You can measure mass using a scale or balance.
Scales either measure mass, or weight - but they are callibrated to show mass (for example, kilograms).
Aging can lead to a coin losing mass due to the oxidation and corrosion of its metal composition, especially in coins made of copper or silver. This process, known as tarnishing, can result in the gradual loss of material from the surface of the coin, which reduces its overall mass over time.
The measure of an object's mass is called mass, and the measure of its velocity is called velocity.
No, if you melt a coin it is still the same mass just in a different form.