Final answer:
The conservation of angular momentum means that a gas cloud swirling around a black hole will form a disk-like structure.
Step-by-step explanation:
The conservation of angular momentum means that a gas cloud swirling around a black hole will form a disk-like structure. When a collapsing nebula begins to rotate faster due to the conservation of angular momentum, the faster-moving material collapses into a flat disk revolving around the central object, like a figure skater spinning more rapidly as she brings her arms in tight to her body. This disk-shaped rotating gas cloud explains the primary motions in the solar system, including the formation of planets that all orbit the same way.