( UPDATED )
- A body's moment of inertia, ( I ), describes how its mass is distributed in relation to an axis of rotation.
- The quantity in rotational motion that is analogous to th e inertia in linear motion is the moment of inertia. The moment of inertia of a rigid body is its resistance to a change in its state of rest or rotational motion.
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| Rigrid body |
- Factors that affect the moment of inertia of a rigrid body are :-
- Mass of the body.
- Distribution of the mass,or shape of the body.
- The position of the axis of rotation.
DEMO VIDEO MOMENT OF INERTIA
APPLICATION:-
QUESTION
- Related to moment of inertia, discuss how to get a longer duration of a top. Why?
ANSWER
From the concept, if we want the longer duration of the top to spin. We need a high inertia ( I ) to maintain the top lap times. So, Top 2 is the suitable because the radius (r) from the point of the axis and mass (m) higher. Using the formula given, we can determine whether the value is high or low inertia ( I ).
I = mr^2 m = mass of top
r = radius from axis of top
unit = kg m^2
- Inertia ( I ) is the resistance of any physical object to a change in its state of motion or rest. It is proportional to an object's mass ( m ) and radius ( r ).
Based on question, found the top with a high value of inertia ( I ) will rotate longer than the top has low of inertia ( I ). because of the mass ( m ) and radius ( r ) of a rotating object that affect the final value of inertia ( I ). Objects that have a high value of inertia is difficult to start the rotation, but when it rotates, it is difficult to stop. like the video above, a ruler who does not have a weight ( mass ) on the front earlier falls ( rotating ) from a ruler who has a weight ( mass ) at the front. This clearly states that the object is rotating with the inertia ( I ) is difficult to start the rotation, and when rotating, it is difficult to stop.
