16. Angular Momentum

What is the angular momentum of a hydrogen atom in a 4p state? Give your answer as a multiple of $\hslash$.

When a bullet spins as it is fired from a rifled barrel, what property of its motion is primarily improved?

Two disks are mounted on the same axis. Disk 1 has a moment of inertia $I_i$ and initial angular velocity ${\omega }_i$. Disk 2, initially at rest, has a moment of inertia $I_r$. If the disks are suddenly coupled together so that they rotate as one unit without external torques, what is the final angular velocity ${\omega }_f$ in terms of $I_i$, $I_r$, and ${\omega }_i$?

Given a rotating object that moves through an angular displacement of $\Delta \theta$ in a time interval $\Delta t$, what is the formula for its average angular speed?

A person of mass $m$ stands at the edge of a frictionless circular platform of mass $M$ and radius $R$, initially at rest. The person walks to the center of the platform. Assuming no external torques act on the system, what is the angular velocity $\omega f_{}$ of the platform after the person reaches the center?

What is the approximate angular speed of the Earth as it rotates about its axis? (Assume one rotation per $\mathrm{sidereal}\mathrm{day}$.)

A clock's minute hand is $0.15 m$ long. What is the angular speed of the tip of the minute hand in radians per second?

Angular momentum measures which of the following physical quantities for a rotating object?

In a rotating solar nebula, where is the angular velocity $\omega$ slowest?