All Flashcards
What is rotational inertia (moment of inertia)?
A measure of an object's resistance to changes in its rotational motion.
What factors does rotational inertia depend on?
Mass and how that mass is distributed relative to the axis of rotation.
Define r in the context of rotational inertia.
The perpendicular distance of each mass element dm to the axis of rotation.
What is Icm in the parallel axis theorem?
The rotational inertia about an axis through the center of mass.
What is d in the parallel axis theorem?
The perpendicular distance between the new axis and the axis through the center of mass.
What is the definition of rotational inertia?
Rotational inertia (moment of inertia) measures an object's resistance to changes in its rotational motion. It depends on mass and its distribution relative to the axis of rotation.
Define 'I' in the context of rotational inertia.
'I' represents rotational inertia, measured in kg⋅m².
What is 'r' in the context of rotational inertia?
'r' is the perpendicular distance from the axis of rotation to the mass (measured in meters).
Define .
is the rotational inertia about the center of mass.
What does represent in the parallel axis theorem?
represents the rotational inertia about a parallel axis.
What is 'M' in the parallel axis theorem?
'M' is the total mass of the system.
What is the effect of increasing the distance of mass from the axis of rotation?
Increasing the distance increases the rotational inertia, making it harder to change the object's rotational motion.
What happens to rotational inertia when an axis of rotation is shifted away from the center of mass?
The rotational inertia increases. This is described by the parallel axis theorem.
What is the effect of a figure skater pulling their arms in during a spin?
Pulling their arms in decreases the distance of their mass from the axis of rotation, decreasing their rotational inertia and increasing their angular speed.