Volume of a Sphere

In this Instructable we'll cover several ways to find the volume of a sphere - a locus of points that are equidistant to a fixed center in a 3D space.

What you're going to possibly need:

• A Sphere
• Distance measuring tool (ruler, caliper)
• Calculator/Pen+Paper
• Graduated cylinder + water
• A brain (you're on Instructables.com - you've already got this...I'm not going to stress common sense all that much)

Step 1 The Volume Formula

The volume of a sphere is (4/3)*pi*r³
where:

• 4/3 is a constant
• Pi is a constant that for our purposes will = 3.14
• r is the radius of the sphere, which is the distance from the center of the sphere to any point on that sphere's surface

Comments

[songkipark]

Dude, GREAT instructable! Still, more to do on your description of the Water Displacement method. You need to explain that the way to find the meniscus is to put you eye level to the flask (or in this case tube), and get the lowest point on the water. And, this method is almost always an estimate, because of the inaccuracy of the water level. That is the main reason that most math teachers don't have a tube and a sphere ready on your tests. It's pretty different with science teachers, because we(referring to me :) almost always have a flask ready, some marbles, and usually the water.
There is also a method to do this with gas, but I did not include it in my "Volume of a sphere." Otherwise, yours is pretty good, from my standpoint.
You can check mine out, here.