Final answer:
A high side float in physics is controlled by the buoyant force. If the density of the liquid is greater than the density of the float, the float sinks. If the density of the liquid is less than the density of the float, the float rises.
Step-by-step explanation:
In the context of physics, a high side float typically refers to a device used in fluid mechanics to measure the level of a liquid in a container. The controlling factor that determines the behaviour of a high side float is the buoyant force acting on it.
When the density of the liquid is greater than the density of the float, it sinks until the buoyant force is equal to the weight of the float. On the other hand, if the density of the liquid is less than the density of the float, it rises until the buoyant force is balanced.
An example of a high side float is a gasoline tank indicator, where the float's position corresponds to the level of gasoline in the tank.