All Flashcards
What is the effect of decreasing the moment of inertia on angular velocity, if angular momentum is conserved?
Angular velocity increases.
What is the effect of an external torque on a system's angular momentum?
The angular momentum changes; it is no longer conserved.
What is the effect of dropping a mass at the edge of a rotating disk on the system's angular velocity?
The angular velocity decreases because the moment of inertia of the system increases.
What is the effect of the gravitational force on a planet's angular momentum in a closed orbit?
Since the gravitational force is a central force, there's no external torque on the planet, so angular momentum is conserved.
What is the effect of a disk bouncing back from a rod after collision on the rod's angular speed?
The rod's angular speed will be greater.
Compare and contrast linear and angular momentum.
Linear momentum: mass in linear motion. Angular momentum: moment of inertia in rotational motion. Both are conserved in closed systems.
Compare the effect on final angular speed when a disk sticks versus bounces off a rod.
Sticking: Rod gains angular momentum. Bouncing: Disk transfers more angular momentum, so the rod's angular speed will be greater.
What are the steps to solve a conservation of angular momentum problem?
1: Identify initial and final states. 2: Determine if external torque is zero. 3: Apply . 4: Solve for the unknown.
How does a skater conserve angular momentum?
1: Skater starts spinning with arms out (high , low ). 2: Skater pulls arms in (low ). 3: Angular velocity increases to conserve angular momentum ( remains constant).