Up next in 10
Moment of inertia
Show More Show Less View Video Transcript
0:00
What is moment of inertia? Moment of
0:02
inertia is the measure of an object's
0:04
resistance to changes in its rotational
0:07
motion about a given axis. Moment of
0:10
inertia plays the same role in
0:12
rotational motion as mass does in linear
0:14
motion.
0:16
It determines how difficult it is to
0:17
start, stop, or change the rotation of
0:21
an object. The value of moment of
0:23
inertia depends not only on the mass of
0:25
the object, but also on how that mass is
0:28
distributed relative to the axis.
0:31
The farther the mass is from the axis,
0:33
the greater the moment of inertia.
0:35
Different objects have different moments
0:37
of inertia depending on their shapes and
0:40
how their mass is arranged. Imagine
0:42
pushing the height of a building. It is
0:44
easier to push it near the handle than
0:46
near the hinges.
0:47
This is because the distance from the
0:49
axis of rotation affects how easily it
0:52
rotates, which is related to moment of
0:55
inertia. Examples: A rotating wheel, a
0:58
spinning disk, a rod rotating about one
1:01
end, Earth rotating about its axis,
1:04
objects with mass distributed far from
1:06
the center having higher inertia
1:08
asterisk asterisk.