# Weight Density

Written by Jerry Ratzlaff on . Posted in Classical Mechanics

Weight is a force on an object accelerated by gravity.  Density is the ratio of the amount of matter in an object compared to its volume.  The basic difference between density and weight is that weight is a measure of the amount of matter in an object, whereas density measures the amount of matter in a unit volume.

## weight DENSITY formula

 $$\large{ W_{\rho} = \frac{m \; g}{g_c} }$$

### Where:

 Units English Metric $$\large{ W_{\rho} }$$  (Greek symbol rho) = weight density $$\large{\frac{lbf-in}{ft^3}}$$ $$\large{\frac{kg-mm}{m^3}}$$ $$\large{ g }$$ = gravity $$\large{\frac{ft}{sec^2}}$$ $$\large{\frac{m}{s^2}}$$ $$\large{ g_c }$$ = gravity conversion constant $$\large{in^4}$$ $$\large{mm^4}$$ $$\large{ m }$$ = mass $$\large{lbm}$$ $$\large{kg}$$