 |
|
| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
|
|
mass
In general, the amount of matter in a body. Mass can be defined more precisely in terms of how difficult it is to change a body’s state of motion or how great is the body’s gravitational effect on other objects. The first of these is called inertial mass (see inertia) and is given by the factor m in Newton’s second law F = ma. The second is called gravitational mass and is the mass corresponding to an object’s weight in a local gravitational field – the m in F = mg for an object on or near the Earth. According to all experiments, the values for m arising from these two definitions are identical. Einstein’s mass-energy relationship also shows that mass and energy are interchangeable.
Related categories
• CLASSICAL MECHANICS
• GRAVITATIONAL PHYSICS
Also on this site:
Encyclopedia of Alternative Energy & Sustainable Living
Encyclopedia of History
Transport Concepts & Designs (partner site)