16. Angular Momentum

Which statement best explains how both planets orbiting the Sun and figure skaters spinning on ice conserve angular momentum ($L$)?

According to the conservation of angular momentum, what happens to the rotational speed of a spinning star if its diameter $d$ increases while no external torque acts on it?

Under which condition is the angular momentum $L$ of a system constant?

Under what condition is the angular momentum $L$ of an object conserved?

Based on the conservation of angular momentum ($L=I\mathrm{C9}$), what happens to the angular velocity ($\mathrm{C9}$) of a figure skater when they pull their arms in during a spin, assuming no external torques act on the system?

Based on the conservation of $\mathrm{angular} \mathrm{momentum}$, how does one expect the planets to spin as they form from a rotating cloud of gas and dust?

According to the conservation of angular momentum ($L$), what happens when a spinning ice skater draws in her outstretched arms?

According to the law of conservation of angular momentum, the angular momentum $L$ of a system remains constant if which of the following conditions is satisfied?

In the context of conservation of angular momentum, consider the system shown in Figure 2, part e. For which of the following diagrams is the $L$ (angular momentum) of the system constant?

An ice skater is spinning with her arms out and is not being acted upon by an external torque. What happens to her angular velocity $\omega$ if she pulls her arms in toward her body?

Two astronauts, both 80 kg, are connected in space by a light cable. When they are 10 m apart, they spin about their center of mass with 6 rad/s. Calculate the new angular speed they'll have if they pull on the rope to reduce their distance to 5 m. You may treat them as point masses, and assume they continue to spin around their center of mass.

Suppose a diver spins at 8 rad/s while falling with a moment of inertia about an axis through himself of 3 kg m². What moment of inertia would the diver need to have to spin at 4 rad/s? 

BONUS: How could he accomplish this?