What instrument is used to find Earth's length?
Moved From Discussion Page - Posted by Aggie Earth doesn't have a 'length.' It has a circumferance, a mass, a volume, even a length of time or age, but it doesn't have a length.
Any instruments that can measure mass and length. (not at the same time, doesnt have to be the same instrument). By measuring the length, height and width of an object you can determine it's volume and by weighing it you can determine it's mass. From these results it's possible to calculate the objects density.