The upthrust, also known as the buoyant force, on an object that floats in water is equal to the weight of the water displaced by the object. This principle is known as Archimedes' principle.
To determine the upthrust, you need to consider the volume of water displaced by the object. The greater the volume of water displaced, the greater the upthrust. The weight of the water displaced is equal to the mass of the water displaced multiplied by the acceleration due to gravity (9.8 m/s² on Earth).
Mathematically, the upthrust (F_up) can be calculated as:
F_up = ρ_water * V_displaced * g
Where:
- ρ_water is the density of water
- V_displaced is the volume of water displaced by the object
- g is the acceleration due to gravity (approximately 9.8 m/s² on Earth)
The upthrust or buoyant force acts in the opposite direction to the force of gravity. When the upthrust is equal to or greater than the weight of the object, the object will float. If the upthrust is less than the weight of the object, the object will sink.
It's worth noting that the density of the object itself plays a crucial role in determining whether it will float or sink. If the object's density is less than the density of water, it will float because it will displace an amount of water greater than its own weight. Conversely, if the object's density is greater than the density of water, it will sink since the weight of the object exceeds the upthrust it experiences.