Get some water measure it in mL or L and then put the object in and measure again. Then Subtract them.
or
Base X Height X Width= Volume
The best way to find the mass is by scale. The best way to find the volume is to submerge the body in a tank or tub filled partially with water (tank or tub must be equipped with volume measurements). The body must be fully submerged to get an accurate reading. Subtract initial volume from final volume (Vf - Vi = volume of object). That's it. If you are looking for densinty, then Density = Mass/Volume.
A graduated cylinder is a good way to find volume. Another way to find volume is to use the following equation: Length x Width x Height. This is a way to find the volume of a rectangular or square item.
Use a graduated cylinder and the water displacement method. Pour the sample of water in the graduated cylinder and find its meniscus. That is its volume.
The best way to find the volume of an irregular shape is to split it up into shapes that you know, find the volumes of those individual pieces, and then add up all of the volumes of the split pieces to get your total volume of the irregular shape.
The best way to find the densities between two rocks is by conducting a displacement test. You will need to measure the volume of water displaced when the rocks are submerged, and then calculate the density using the mass of the rocks and the displaced water.
A volume has to be a three dimensional thing, otherwise the volume is zero.
same way u find the volume of anything else.. use a formula
The best way to find the volume of an irregular solid is to submerge it in a liquid and see how much the liquid rises. You can also use calculus and tripple integrals, but that gets really sticky.
You can't. Volume is only for 3 dimensional shapes. You won't find a way of using volume in any kind of 2 dimensional stuff.
crescendo
I don't believe there is a way to find the mass of an object knowing only the diameter of the object. If you had the volume, or some other measurements sure. the best bet would be just to weigh it, or find the volume using the principles of displacement.
You can't. With only the radius, there is no way to know how tall the cylinder is, and therefore no way to determine its volume. Sorry :(