Math problem

[galt11]

Ok, time to break out the calculators. I am trying to find a formula that would allow me to calculate the weight of an object if I am given its circumference, diameter, and height. I can also make an approximation of its density. Does such a formula exist. Help.

Adam

[Matt Cheely]

Density = Mass / Volume

Volume of a cylinder = pi r^2 h

Weight = mass * gravity

[ChuckS]

It sounds like you are describing a cylinder. If so, you first find the circular area (Pi time the square of the radius). For your thing it is 3.14 * d/2 * d/2. The units of the answer are square whatever units D is. You take that number and multiply it by the height (in the same units as d) and you get the volume of the cylinder in cubic whatevers. Use the volume with the density of the stuff to figure out the weight.

Later,

Chuck

Pi*R*R*H

[Matt Cheely]

So if you want to go all the way:

Density * pi * r^2 * h * gravity = weight

[galt11]

The object in question could best be described as ball shaped

[Matt Cheely]

Density * 4/3 * pi * r^3 * gravity = weight

[Dave Gundry]

If the density is given in metric or SI units, multiply by 9.8m/(s^2) to get weight. If it is given in pounds or ounces, you probably don't need to multiply by g (which would be 32.2 ft/(s^2) in the US system).

[galt11]

Thanks everyone. I will give it a shot.

Adam