All Flashcards
How do linear momentum and angular momentum compare?
Linear momentum: mass in motion in a straight line. Angular momentum: rotational inertia in motion around an axis.
What is the difference between torque and angular impulse?
Torque: A twisting force that causes rotation. Angular impulse: The change in angular momentum caused by a torque acting over a time interval.
Compare rigid and non-rigid systems in terms of angular momentum.
Rigid systems: Angular speed can only be changed by external torques. Non-rigid systems: Angular speed can be changed by altering mass distribution.
Compare the effects of internal and external torques on a system's angular momentum.
Internal Torques: Redistribute angular momentum within the system, but the total remains constant. External Torques: Change the total angular momentum of the system.
Compare linear impulse and angular impulse.
Linear Impulse: Change in linear momentum. Angular Impulse: Change in angular momentum.
What is the effect of applying an external torque to a rotating object?
It changes the object's angular momentum.
What happens when a figure skater pulls their arms in?
Their moment of inertia decreases, and their angular speed increases, conserving angular momentum.
What is the effect of no net external torque on a system?
The total angular momentum of the system is conserved.
What happens to angular speed if the moment of inertia decreases in a closed system?
The angular speed increases to conserve total angular momentum.
What is the effect of angular impulse on an object?
It changes the object's angular momentum.
What is angular momentum?
The rotational equivalent of linear momentum; a measure of an object's resistance to change in its rotation.
Define moment of inertia.
A measure of an object's resistance to changes in its rotational speed about an axis of rotation. It depends on the mass and the distribution of mass relative to the axis.
What is torque?
A twisting force that tends to cause rotation. It is the rotational equivalent of linear force.
Define angular impulse.
The change in angular momentum of an object. It is equal to the net external torque multiplied by the time interval over which the torque acts.
What is net external torque?
The sum of all torques acting on a system due to forces external to the system.
Define angular velocity.
The rate of change of angular displacement with respect to time, typically expressed in radians per second.