What determines if an object will sink or float in water?

The determination of whether an object will sink or float in water is primarily based on its density in relation to the density of water. Density is defined as mass per unit volume; it describes how much matter is packed into a given space.

When an object is placed in a fluid like water, it will float if its density is less than that of water (approximately 1 gram per cubic centimeter). Conversely, if the object's density is greater than that of water, it will sink. This principle is rooted in Archimedes' principle, which states that an object submerged in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced by the object.

While other factors like volume and shape can influence how an object behaves in water, they do not fundamentally determine whether an object sinks or floats. For instance, a large object may be less dense than water and therefore float, while a small object can sink if its density is greater, irrespective of its volume or shape. The object's color has no bearing on its buoyancy. Therefore, density is the key characteristic that dictates the floating or sinking behavior in water.