Standard 3/Middle School
the non-contact forces exerted by magnets, electrically charged objects,
Some forces are exerted from
a distance with objects not touching. Examples of these forces are magnetic
attraction or repulsion, attraction or repulsion between electric charges,
and gravitational attraction.
These types of forces are
called non-contact forces, because they occur between objects that don’t
touch. These forces can be demonstrated by the following:
The magnetic poles of a magnet will either repel or attract other magnet
poles of another magnet. For example, the north pole of one magnet will
repel the north pole of the other magnet (same thing will occur with two
south poles), but the north pole of one magnet will attract the south pole
of the other magnet.
Electrically charged objects
will either repel other electrically charged objects if their charges are
alike, such as a positively charged object near another positively charged
object, or will attract other electrically charged objects, such as if one
object is charged positively and the other negatively. Unlike charges
attract, like charges repel.
Gravity is an attractive
force that occurs between any two objects that have mass. These objects are
attracted to each other (Moon held in orbit by the Earth). The greater the
mass of the object, the stronger the gravitational pull. Increased distance
between objects results in decreased gravitational pull.
- Describe forces exerted from a distance with
objects not touching.
See Forces and motion, (SCI.IV.3.MS.2).
See Weight and mass, (SCI.IV.1.MS.2).
Key Concept / Real World Context / Instructional
Example / Assessment Example / Resources