Boyle's law states that "for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional". Expressed as a formula, that's \(\frac{P_1}{P_2} = \frac{V_2}{V_1}\)

Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.

The Joule (J) is the standard unit of energy and has the unit \({kg \times m^2} \over s^2\).

Mass is a measure of the amount of matter in an object. In general, larger objects have larger mass than smaller objects but mass ultimately depends on how compact (dense) a substance is.

The six types of simple machines are the lever, wheel and axle, pulley, inclined plane, wedge, and screw.