Lesson: Chapter 4 — Newton's Laws of Motion

4.3. Mass and weight 4 of 4

Mass and weight compared

Everything this section covered, brought into one table.

	Mass	Weight
Is	The amount of matter contained	The force pulling it earthwards
Unit	kg	N
Type	Scalar	Vector
Formula	—	m g
From place to place	Unchanged	Changes
On the moon	The same value	About one sixth

Mass has no formula because it is a fundamental quantity — it is not derived from other quantities.

A way to remember

"How much matter is it?" — mass, in kilograms. "How hard is it being pulled?" — weight, in newtons.

At the end of the chapter

A force produces an acceleration (laws 1 and 2); a force never exists alone (law 3); the difficulty of stopping motion is momentum; and weight is the force gravity applies to a mass.