Module 4 Glossary

 

density: the mass per unit volume of an object

 

gravitational field: a field created by any object with mass, extending outward in all directions, which determines the influence of that object on all others

 

gravity: a force of attraction towards the centre of objects

 

inverse square law: any physical law stating that some quantity is inversely proportional to the square of the distance from a point

 

mass: the property of physical objects that, roughly speaking, measures the amount of matter they contain

 

Newton's law of universal gravitation: summarized mathematically as

 

proportionality constant: the constant value of the ratio of two proportional quantities

 

torsion balance: a measuring instrument designed to measure small forces by the torsion (twisting) they exert on a thin wire

 

universal gravitational constant: the value G in the equation  summarizing Newton's law of universal gravitation