/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 33 A wooden block of volume \(5.24 ... [FREE SOLUTION] | 91影视

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A wooden block of volume \(5.24 \times 10^{-4} \mathrm{~m}^{3}\) floats in water, and a small steel object of mass \(m\) is placed on top of the block. When \(m=0.310 \mathrm{~kg}\), the system is in equilibrium and the top of the wooden block is at the level of the water. (a) What is the density of the wood? (b) What happens to the block when the steel object is replaced by a second steel object with a mass less than \(0.310 \mathrm{~kg}\) ? What happens to the block when the steel object is replaced by yet another steel object with a mass greater than \(0.910 \mathrm{~kg}\) i

Short Answer

Expert verified
The density of the wooden block is \(1000 \mathrm{~kg/m^3}\). If the mass of the steel object decreases, the wooden block raises a bit above the water level. If the mass of the steel object increases, the wooden block sinks further into the water.

Step by step solution

01

Finding the density of the wooden block

Firstly, we understand that when the system is at equilibrium, the forces must be balanced. This means that the total weight of the block (wooden block and the steel object) equals the weight of the water displaced by the block. Weight is obtained by the product of mass and gravitational force.鈥 Mathematically, this can be expressed as:\[\text{{Weight of the wood}} = \text{{Weight of water displaced by the wooden block}}\]or,\[\text{{Mass of the wood}} \times g = \text{{Density of water}} \times V \times g\]Here, \[\text{{Mass of the wood}} = \text{{Density of the wood}} \times \text{{Volume of the wood}},\]Therefore, we have:\[\text{{Density of the wood}} \times \text{{Volume of the wood}} \times g = \text{{Density of water}} \times V \times g\]which simplifies to: \[\text{{Density of the wood}} = \text{{Density of water}}\]As the density of water is \(1000 \mathrm{~kg/m^3}\), the density of the wooden block is also \(1000 \mathrm{~kg/m^3}\).
02

Analyzing the effect of changing the mass of the steel object

The total weight of the block (wood and steel) must always be equal to the weight of water displaced. If the mass of the steel object is decreased, this means the total weight of the block would decrease. To balance this, the wooden block will raise a little above the water level decreasing the weight of the displaced water.On the other hand, if the mass of the steel object is increased, the total weight of the block increases. To keep equilibirum, the wooden block will sink a little more into the water, increasing the volume of water displaced and thus the weight of the displaced water.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Density
Density is a measure of how much mass a substance contains in a given volume. It's an important property that helps us understand how different objects will behave in a fluid, like water.

For instance, the density of an object determines whether it will float or sink. In our problem, we have a wooden block with a certain volume floating in water. When an object like the block is floating, its density is often less than the density of the fluid it's placed in. This is why the wooden block floats in water.

When the steel object is added, it affects the overall density of the system (wood plus steel object). The balance in densities allows us to calculate the density of the wooden block through the relationship between the mass of the wood, volume of the wood, and the density of water:
  • Density of wood: The amount of wood's mass per unit volume.
  • Density of water: Typically, 1000 kg/m鲁 in most problems.
  • Equilibrium: The point when the overall weight of the system and water displaced is equal.
Using these principles, we find that, at equilibrium, the density of the wood equals the density of the water because the block is just level with the water.
Equilibrium
Equilibrium occurs when the forces acting upon an object or system are balanced, resulting in a stable condition. In the context of our buoyancy problem, equilibrium plays a critical role in determining how much of the block is submerged in water.

When the system is in equilibrium:
  • The upward buoyant force, which is the weight of the fluid displaced, equals the downward gravitational force on the system (wood plus steel object).
  • This balance allows us to determine if an object will float or sink further based on additional mass.
  • The equilibrium condition is expressed mathematically as the equality of these two forces.
Adding the mass of the steel object shifts this balance, but as long as the forces are balanced, equilibrium is maintained.

The system comes to rest when the wooden block is exactly at the water level, a perfect indication of equilibrium. This is because the total weight is precisely supported by the displaced water's weight, causing it not to rise or sink further.
Displacement
Displacement within the context of buoyancy refers to the amount of fluid that is pushed aside by an object submerged or floating in it. This concept is a cornerstone of buoyancy's principles because it directly ties the fluid's volume to the force acting on the object.

When an object is placed in a fluid:
  • The volume of the fluid displaced is equal to the volume of the part of the object submerged.
  • For the wooden block, displacement determines how much of it sits underwater.
  • The weight of the displaced fluid generates a buoyant force that acts upward, opposing the weight of the object.
As the mass of the steel object changes, it alters how much the block displaces water:
  • If less mass is placed, the block rises, displacing less water.
  • Conversely, with more mass, the block sinks further, displacing more water.
Understanding displacement helps predict how objects interact with fluids under different masses and ensures stability in our floating wooden block scenario.

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Most popular questions from this chapter

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