Final answer:
The difficulty in starting the wheel of a roulette table spinning is due to inertia, and once it's started, it keeps spinning due to the conservation of angular momentum.
Step-by-step explanation:
The difficulty in starting the wheel of a roulette table spinning is due to inertia. Inertia is the tendency of an object to resist any change in its motion, including starting or stopping. The roulette wheel has a large mass and it requires a significant force to overcome its inertia and set it in motion.
Once the wheel is spinning, it continues to spin due to the conservation of angular momentum. Angular momentum is the property of a rotating object that depends on its mass, shape, and rotational speed. In the case of the roulette wheel, once it's set in motion, there is minimal friction acting against it, allowing it to keep spinning.
An example that helps illustrate the conservation of angular momentum is the ice skater pulling her arms in. By pulling her arms closer to her body, she reduces her moment of inertia, which causes her rotational speed to increase according to the conservation of angular momentum. This principle allows the ice skater to spin faster and faster without exerting a torque to spin faster.