What do you want to measure about the marble? Its diameter, radius, circumference, volume, mass, density...?
I would use a micrometer. A caliper would do as well.
14mm
That depends a lot what you want to measure: its diameter, surface area, volume, mass, density, color, hardness, etc.
Internal diameter.
What do you want to measure about the marble? Its diameter, radius, circumference, volume, mass, density...?
millimetres or mm
milimetersMilliliter
That depends what aspect of a marble you want to measure, for example its diameter, its mass, its density, its color, etc.
That depends what you want to measure: its diameter, its mass, its weight, its color, etc.
I would use a micrometer. A caliper would do as well.
If you have calibrated eyeballs
14mm
6.5cm
That depends a lot what you want to measure: its diameter, surface area, volume, mass, density, color, hardness, etc.
To find the volume of a steel marble, you can use the formula for the volume of a sphere, which is V = (4/3)πr^3, where r is the radius of the marble. Measure the diameter of the marble using a caliper, then divide it by 2 to get the radius. Plug the radius into the formula and calculate the volume using the value of π. This will give you the volume of the steel marble in cubic units.
13.2 cm, if the given measure is the diameter.13.2 cm, if the given measure is the diameter.13.2 cm, if the given measure is the diameter.13.2 cm, if the given measure is the diameter.