Apparent Weight in Seawater Conversion

I created this simple tool to calculate the apparent weight in seawater for lead and steel objects. I also included the reverse calcution and a conversion for weight of lead in air to weight of steel in air such that they have the same apparent weight in water. More materials can be added.

Apparent weight refers to the weight of an object when it is submerged in a fluid, such as seawater. When an object is submerged in a fluid, it experiences a buoyant force that opposes its weight, making it seem lighter. This buoyant force is equal to the weight of the fluid displaced by the object.

To convert the true weight of an object to its apparent weight in seawater, follow these steps:

1. Calculate the buoyant force (F_b): To calculate the buoyant force, you need the volume of the object (V) and the density of the seawater (ρ_seawater). The density of seawater typically ranges from 1020 to 1030 kg/m³, depending on temperature and salinity.

F_b = V * ρ_seawater * g

where:

• F_b = buoyant force (N)
• V = volume of the object (m³)
• ρ_seawater = density of seawater (kg/m³)
• g = acceleration due to gravity (approximately 9.81 m/s²)

2. Calculate the true weight of the object (W_true): To calculate the true weight of the object, you need the mass of the object (m) and the acceleration due to gravity (g).

W_true = m * g

where:

• W_true = true weight of the object (N)
• m = mass of the object (kg)
• g = acceleration due to gravity (approximately 9.81 m/s²)

3. Calculate the apparent weight of the object in seawater (W_apparent): Subtract the buoyant force (F_b) from the true weight of the object (W_true) to obtain the apparent weight in seawater.

W_apparent = W_true - F_b

where:

• W_apparent = apparent weight of the object in seawater (N)
• W_true = true weight of the object (N)
• F_b = buoyant force (N)

By following these steps, you can convert the true weight of an object to its apparent weight when submerged in seawater. This conversion is important for various applications, such as designing and analyzing underwater structures, equipment, or vehicles, and understanding the behavior of objects in the marine environment.