Mass
Physics: Cambridge International GCSE Supplement, topic 1.3.1
Mass
The mass of an object is a measure of the amount of matter it contains. It is the quantity of matter in an object at rest relative to the observer. The mass of an object is constant. It is the same on Earth, on the Moon and in space.
Amount of matter
- An object's mass is a measure of the amount of matter that it contains.
Inertia
- An object's mass is also a measure of how difficult it is to change the object's motion.
- This is called inertia.
- An object with a high mass has more inertia than an object with a lower mass.
- It is difficult to move an object with a high mass (and high inertia), and once it is moving, the object’s motion is hard to stop.
Test yourself on Mass
Which of the following are true of mass and inertia?
Which of these is the correct definition of inertia?
Why is an object with a high mass harder to stop once it is moving?
Select the correct statement for each pair.