Name: floating block buoyancy and center of buoyancy
Uploaded: 2025-02-13T15:43:11.000Z
Duration: 1 min 11 s
Channel: JoVE

Consider a wooden block with dimensions 1.25 meters wide, 2 meters deep, and 4 meters long floating in water held in a rectangular container.
The specific gravity of wood is 0.64, and the weight of water is 1025 kg(f)/m3.
The objective is to determine the volume of liquid displaced by the block and locate the block&#39;s center of buoyancy.
The weight of the liquid displaced by the block is equal to the weight of the block, as per Archimedes&#39; principle.
The volume of water displaced can be calculated by dividing the block&#39;s weight by the unit weight of water.
Once the submerged block&#39;s depth is known, the position of the center of buoyancy can be calculated.
This depth can be obtained by equating the volume of the block&#39;s immersed portion to the volume of the water displaced by the block.
The center of buoyancy is located at the center of gravity of the submerged part of the block, which is at half the depth of the submerged portion.

design example: application of archimedes' principle

Design Example: Application of Archimedes' Principle

Archimedes&#39; principle is fundamental in analyzing the buoyant force and stability of floating bodies. In this example, a wooden block with a rectangular section floats in seawater. Based on the block&#39;s dimensions, its specific gravity and the specific weight of seawater are used to find the volume of water displaced and the center of buoyancy.
The volume of seawater displaced by the block is determined by first calculating the block&#39;s weight. This is done by multiplying the block&#39;s volume by its specific gravity. According to Archimedes&#39; principle, the weight of displaced water is equal to the weight of the block. The volume of displaced water is then found by dividing the block&#39;s weight by the unit weight of seawater.
The center of buoyancy, which is the centroid of the displaced water volume, indicates where the buoyant force acts. To locate this point, the immersed depth is calculated by equating the submerged portion&#39;s volume to the volume of displaced water. The center of buoyancy is positioned at half the immersed depth from the bottom of the block, representing the equilibrium point where the buoyant force balances the weight of the block.

Consider a wooden block with dimensions 1.25 meters wide, 2 meters deep, and 4 meters long floating in water held in a rectangular container.
The specific ...

design-example-application-of-archimedes-principle

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JoVE Core

Civil Engineering

Unit 1

Fluid Statics

KEY TERMS AND CONCEPTS

floating block buoyancy and center of buoyancy

Archimedes' principle is used to analyze the buoyant force on a wooden block that floats in seawater. The block has a rectangular section, and its dimensions, specific gravity, and the specific weight of seawater are used in the calculation. This setup shows how floating bodies stay in equilibrium.

The first step is to find the weight of the block from its volume and specific gravity. Then Archimedes' principle is applied. The weight of the displaced water must equal the weight of the block. The displaced seawater volume is found by dividing the block's weight by the unit weight of seawater.

Next, the center of buoyancy is located. The center of buoyancy is the centroid of the displaced water volume, and it shows where the buoyant force acts. To find it, the immersed depth is calculated by matching the submerged volume to the volume of displaced water. The center of buoyancy is then half the immersed depth from the bottom of the block, which marks the balance point between the block's weight and the buoyant force.

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buoyancy and stability for submerged and floating bodies

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How Buoyancy Keeps Bodies Stable in Water

Buoyancy and stability explain how submerged and floating bodies behave in a fluid. When a body is fully or partly under water and stays still, the fluid pushes upward on it. That upward push is called the buoyant force. The buoyant force acts through the center of buoyancy. This is the center of the displaced fluid volume. Archimedes’ principle says the buoyant force equals the weight of the fluid displaced by the body. Stability describes whether a body can return to its original position...

Archimedes' principle is used to analyze the buoyant force on a wooden block that floats in seawater. The block has a rectangular section, and its dimensions, specific gravity, and the specific weight of seawater are used in the calculation. This setup shows how floating bodies stay in equilibrium. The first step is to find the weight of the block from its volume and specific gravity. Then Archimedes' principle is applied. The weight of the displaced water must equal the weight of the block.

key terms and concepts

Use Archimedes' principle to calculate a floating wooden block's displaced seawater volume, immersed depth, and center of buoyancy in a clear design example.

Floating Block Buoyancy and Center of Buoyancy | JoVE K12

JoVE Core Civil Engineering offers a foundational exploration of essential construction materials such as bricks, stones, steel, wood, and concrete, along with fluid mechanics topics like flow over immersed bodies, open channel flow, and dimensional modeling. It also covers key surveying concepts, including leveling, traverse adjustments, curve design, topographic mapping, and geospatial technologies (GPS & GIS). Science-in-action videos showcase laboratory research on materials, fluids, and surveying practices in real-world engineering systems.

Floating Block Buoyancy and Center of Buoyancy

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