Hukum Archimedes ( Tekanan Zat Dan Penerapannya Dalam Kehidupan Sehari hari )

Guru IPA

11 Jan 202108:04

Summary

TLDRThis video explores Archimedes' Principle, explaining how objects experience a buoyant force when submerged in a fluid, causing them to seem lighter. It details the mathematical relationship between buoyant force, weight of displaced fluid, and gravitational acceleration. The principle is applied to explain how ships float and submarines control their buoyancy by adjusting their weight. The video concludes with a call to action for viewers to subscribe to the channel.

Takeaways

🌊 The Archimedes' Principle states that when an object is submerged in a fluid, it experiences an upward buoyant force equal to the weight of the fluid displaced by the object.
📉 The buoyant force (Fa) can be mathematically expressed as Fa = Wb - Wa, where Wb is the weight of the object in the fluid and Wa is the weight of the object in air.
🔢 The weight of the displaced fluid (Wcp) is calculated by multiplying the mass of the fluid displaced by gravity, expressed as Wcp = mcp * g, where mcp is the mass of the fluid displaced and g is the acceleration due to gravity.
💧 The mass of the fluid displaced (mcp) is the product of the fluid's density (ρ), the gravitational constant (g), and the volume of the fluid displaced (Vcp), so Wcp = ρ * g * Vcp.
🚢 Archimedes' Principle is fundamental to the design of ships and submarines, determining whether an object will float or sink based on the balance between its weight and the buoyant force.
⬆️ An object will float if the maximum buoyant force is greater than its weight, while it will sink if the maximum buoyant force is less than its weight.
🏊‍♂️ An object will remain neutrally buoyant if the maximum buoyant force equals its weight, allowing it to hover at a certain depth.
🛳️ Ships made of metal, which typically have a higher density than water, can float because they displace a large enough volume of water to equal their weight.
🌌 Submarines can control their buoyancy by adjusting their weight, either by taking in water to increase it or expelling water to decrease it.
📉 When a submarine wants to sink, it takes in water, increasing its total weight beyond the buoyant force, allowing it to descend.
⬆️ To make a submarine rise, it expels water, reducing its total volume and weight, making the buoyant force greater than its weight, causing it to ascend.

Q & A

What is the Archimedes' principle discussed in the script?
-The Archimedes' principle is a law of physics stating that the upward buoyant force exerted on a body immersed in a fluid is equal to the weight of the fluid that the body displaces.
How does the buoyant force affect an object submerged in a fluid?
-The buoyant force acts on an object submerged in a fluid in an upward direction, opposing the weight of the object. This force is equal to the weight of the fluid displaced by the object.
What is the mathematical representation of the buoyant force according to the script?
-The mathematical representation of the buoyant force (Fa) is the weight of the displaced fluid (WBA) minus the weight of the object in air (WB). It can also be represented as Fa = ρ_liquid * g * V_liquid, where ρ_liquid is the density of the liquid, g is the acceleration due to gravity, and V_liquid is the volume of the liquid displaced.
Why does an object appear to weigh less when submerged in water?
-An object appears to weigh less when submerged in water because the buoyant force exerted by the water counteracts some of the object's weight.
How does the density of a liquid affect the buoyant force on an object?
-The buoyant force is directly proportional to the density of the liquid. A higher density liquid will exert a greater buoyant force on an object for the same volume of liquid displaced.
What is the relationship between the volume of the displaced liquid and the buoyant force?
-The buoyant force is directly proportional to the volume of the liquid displaced by the object. More volume displaced means a greater buoyant force.
How does the script explain the ability of a submarine to float or sink?
-The script explains that a submarine can adjust its buoyancy by altering its weight. It can sink by taking in water into its ballast tanks, increasing its weight, and it can float by expelling water from the tanks, decreasing its weight.
What is the condition for an object to float according to the script?
-An object will float if the maximum buoyant force is greater than its weight.
What is the condition for an object to sink according to the script?
-An object will sink if the maximum buoyant force is less than its weight.
What is the condition for an object to remain neutrally buoyant as described in the script?
-An object will remain neutrally buoyant if the maximum buoyant force is equal to its weight.
Why do ships made of metal, which is denser than water, not sink?
-Ships made of metal do not sink because they are designed to displace a large volume of water, which results in a buoyant force equal to or greater than the weight of the ship.

Outlines

00:00

🌊 Archimedes' Principle Explained

This paragraph discusses Archimedes' Principle, which explains why objects appear to lose weight when submerged in a fluid. It clarifies that the weight loss is not due to a reduction in mass but rather due to an upward buoyant force that opposes the object's weight. The principle is mathematically represented as the buoyant force (Fa) equal to the weight of the displaced fluid (WBA) minus the weight of the object in air (WB). The paragraph further explains that the buoyant force is equal to the weight of the fluid displaced by the object, which can be calculated using the mass of the displaced fluid, gravity, and the volume of the displaced fluid. This principle is crucial for understanding why objects float or sink and is applied in the design of ships and submarines.

05:00

🚢 How Ships Float and Submarines Dive

The second paragraph elaborates on how ships and submarines utilize the principles of buoyancy and gravity to float or dive. Ships float because they can displace a significant volume of water, creating a buoyant force equal to their weight. Submarines, on the other hand, can adjust their buoyancy by filling or emptying ballast tanks with water. When a submarine wants to dive, it increases its weight by taking in water, which exceeds the buoyant force, causing it to sink. To stop descending at a certain depth, water is expelled from the tanks, balancing the weight with the buoyant force, allowing the submarine to hover. To surface, water is expelled from the ballast tanks, reducing the submarine's volume and thus its weight, making the buoyant force greater than the weight, causing the submarine to rise. The paragraph concludes with a call to action for viewers to subscribe to the channel.

Mindmap

Keywords

💡Archimedes' Principle

Archimedes' Principle is a fundamental concept in fluid mechanics that states that the upward buoyant force exerted on a body immersed in a fluid is equal to the weight of the fluid that the body displaces. In the video, this principle is discussed to explain why objects float or sink in water. It is central to understanding the behavior of objects in different liquids and is illustrated by explaining that when an object is submerged, it experiences an upward force equal to the weight of the displaced fluid.

💡Buoyant Force

Buoyant Force is the upward force exerted by a fluid that opposes the weight of an immersed object. The video script explains that this force is what causes objects to appear lighter in water, as it counteracts gravity. The concept is crucial in understanding the principle discussed and is exemplified by the phrase 'gayo apung' which translates to 'buoyant force' in the context of the video.

💡Displaced Fluid

Displaced Fluid refers to the volume of fluid that is pushed aside by an object when it is submerged. The video uses this term to explain how the weight of the displaced fluid is equal to the buoyant force acting on the object. This is a key part of Archimedes' Principle, as the volume of displaced fluid directly influences the magnitude of the buoyant force.

💡Weight

Weight is the force exerted on an object due to gravity and is measured in Newtons. In the video, weight is used to contrast with buoyant force, showing that when an object is submerged in a fluid, its apparent weight decreases because the buoyant force reduces the net force acting on it. The script mentions 'WBA' which stands for 'Weight in Air' and 'WB' which stands for 'Weight in Fluid' to illustrate this concept.

💡Density

Density is defined as mass per unit volume and is a property of a substance. The video mentions that the density of a substance ('massa jenis zat cair' in Indonesian) is crucial in determining whether an object will float or sink. A higher density of the displaced fluid compared to the object's density results in a greater buoyant force, which can cause the object to float.

💡Submarine

A submarine is a watercraft capable of operating underwater. The video discusses how submarines use the principle of buoyancy to control their depth by adjusting their weight relative to the buoyant force. This is achieved by flooding or emptying ballast tanks, which changes the submarine's overall density and thus its buoyancy.

💡Gayo Apung

Gayo Apung, meaning 'buoyancy' in Indonesian, is the property that allows objects to float or be suspended in a fluid. The video explains how objects become buoyant by displacing fluid, creating an upward force. This is exemplified by the script's discussion of how a submarine can control its buoyancy to ascend or descend in water.

💡Volume

Volume is the measure of the space occupied by an object or fluid. In the context of the video, volume is important because the buoyant force is directly related to the volume of the fluid displaced by an object. The script mentions 'volume cair yang dipindahkan' or 'displaced fluid volume' as a factor in calculating the buoyant force.

💡Gravity

Gravity is the force that attracts two bodies towards each other, and it plays a significant role in the video's discussion of buoyancy. The weight of the displaced fluid, which contributes to the buoyant force, is a result of gravity. The script uses the term 'gravitasi' to describe this force, which is essential for calculating the buoyant force acting on an object.

💡Floating

Floating is the state where an object rests on the surface of a liquid without sinking. The video explains that an object will float if the buoyant force is greater than its weight. This is demonstrated by the script's discussion of how objects become lighter in water due to the buoyant force acting against gravity.

💡Sinking

Sinking is the process of an object falling to the bottom of a liquid due to the force of gravity being greater than the buoyant force. The video script mentions that if the maximum buoyant force is less than the weight of an object, it will sink, which is a direct application of Archimedes' Principle.

Highlights

Discussing Archimedes' Principle on the channel.

When an object is submerged in water, it experiences a buoyant force.

The buoyant force is equal to the weight of the displaced fluid.

Archimedes' Principle states that an object submerged in a fluid experiences an upward force equal to the weight of the fluid displaced.

Objects become lighter when measured in water due to the buoyant force.

The weight of the displaced fluid is calculated as the product of the fluid's mass, gravity, and the volume of fluid displaced.

The principle is fundamental to the design of ships and submarines.

An object will float if the maximum buoyant force is greater than its weight.

An object will sink if the maximum buoyant force is less than its weight.

An object will remain neutrally buoyant if the maximum buoyant force equals its weight.

Metals, despite being denser than water, can be part of floating structures like ships.

Ships float because they displace a large volume of water, equal to their weight.

Submarines can control their buoyancy by adjusting their weight.

Submarines sink by taking in water, increasing their total weight.

Submarines float by expelling water, reducing their total weight to match the buoyant force.

The principle explains how submarines can dive, hover, and surface.

The video concludes with a call to action for viewers to subscribe to the channel.