If I was you i would use millimetres or centimetres.
Grams
I would use a micrometer. A caliper would do as well.
What do you want to measure about the marble? Its diameter, radius, circumference, volume, mass, density...?
It would be the simplest way to do so.
You would use area. I would use the meter2. Okay
Grams
I would use a micrometer. A caliper would do as well.
milimetersMilliliter
That depends what aspect of a marble you want to measure, for example its diameter, its mass, its density, its color, etc.
millimetres or mm
Mass is measured in kilograms. Weight is measured in newtons. If you are asking which unit to choose to measure then mass of a marble, then you need to use the submultiple of the kilogram, the gram.
You can measure the speed of a marble by using a stopwatch to record the time it takes for the marble to travel a known distance. Divide the distance by the time to calculate the speed in units such as meters per second or feet per second. Alternatively, you can use a motion sensor or tracking software to measure the speed of the marble in real time.
What do you want to measure about the marble? Its diameter, radius, circumference, volume, mass, density...?
It would be the simplest way to do so.
I would use a fabric tape measure.I would use a fabric tape measure.
You would use area. I would use the meter2. Okay
Calipers would be accurate, a micrometer would probably be most accurate. there's a few options, depends on your purpose.