What does an object have to have so that it can float on top of water?
The object must be less dense than water or displace a volume of water greater than the mass of the object
It has to be light
To understand why an object floats on water, you need to consider the concept of buoyancy and density. Buoyancy is the upward force exerted on an object submerged in a fluid, such as water. Density, on the other hand, is the mass of an object divided by its volume.
For an object to float on water, it must meet one of two conditions:
1. The object's density must be less than the density of water: Density is a measure of how much mass is packed into a specific volume. If the object is less dense than water, it will float. This means that its weight (downward force) is less than the buoyant force acting upon it (upward force). For example, a Styrofoam ball is less dense than water, so it floats.
2. The object must displace a volume of water greater than its own mass: This principle, known as Archimedes' principle, states that when an object is submerged in a fluid, it displaces an amount of fluid equal to its own weight. If the displaced water has a mass greater than the object itself, the object will float. For example, a ship displaces a large volume of water that weighs more than the ship itself, allowing it to float.
In summary, for an object to float on top of water, it must be less dense than water or displace a volume of water greater than its own mass.