/*! 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 45 Emptying a conical tank An inver... [FREE SOLUTION] | 91影视

91影视

Emptying a conical tank An inverted cone (base above the vertex) is \(2 \mathrm{m}\) high and has a base radius of \(\frac{1}{2} \mathrm{m} .\) If the tank is full, how much work is required to pump the water to a level \(1 \mathrm{m}\) above the top of the tank?

Short Answer

Expert verified
Answer: The amount of work required to pump the water to a level 1 meter above the top of the tank is approximately 7746.96 Joules.

Step by step solution

01

Calculate the Volume of the Cone

First, find the volume of the conical tank using the formula V = (1/3)蟺r虏h, where r is the base radius and h is the height of the cone. Here, r=1/2m and h=2m. V = (1/3)蟺(1/2)^2 脳 2 = (1/3)蟺(1/4) 脳 2 = (1/6)蟺 m鲁
02

Set up the Integral

To calculate the work done at each level of the tank, we need to set up an integral. Let x be the distance from the vertex of the cone, and let y be the distance from the center of the base of the cone. We can use similar triangles to relate x and y: y / x = (1/2) / 2 , so y = x/4. The volume of a horizontal slice of the tank at a height x is given by: dV = 蟺y^2 dx = 蟺(x/4)^2 dx = 蟺x虏/16 dx To find the work done at each level, we need to multiply the volume of the slice by the density of water (蟻), the gravitational constant (g), and the distance that the force acts (3 - x): dW = 蟻g(3-x)dV = 蟻g(3-x)蟺x虏/16 dx Now we can set up the integral: W = 鈭(蟻g(3-x)蟺x虏/16) dx from x=0 to x=2
03

Solve the Integral

Now we will solve the integral to find the amount of work required to pump the water 1 meter above the top of the tank: W = 蟻g蟺/16 鈭(3x虏 - x^3) dx from x=0 to x=2 Evaluating the integral: W = 蟻g蟺/16 [x鲁 - x^4/4] from x=0 to x=2 W = 蟻g蟺/16 [(2^3 - (2^4)/4) - (0^3 - (0^4)/4)] W = 蟻g蟺/16 [(8 - 4) - (0 - 0)] W = 蟻g蟺/16 (4)
04

Insert Constants and Calculate Work

Now that we have evaluated the integral, we can insert the constants for the density of water (蟻 = 1000 kg/m鲁) and the gravitational constant (g = 9.81 m/s虏): W = (1000)(9.81)(蟺/16)(4) W 鈮 7746.96 J Therefore, the amount of work required to pump the water to a level 1 meter above the top of the tank is approximately 7746.96 Joules.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

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

Work Done by Pumping
When a fluid like water needs to be moved, there is a physics concept that comes into play called 'work done by pumping'. You might have wondered what physical effort or energy is required to move water from a lower level to a higher level, such as pumping it out of a conical tank. The 'work' in this context is the energy transferred to the water to move it against gravity.

Work can be calculated by multiplying the force needed to lift the water and the distance over which this force acts. In our conical tank problem, we need to determine how much energy it takes to pump the water up 1 meter above the tank's top. Understanding this concept is crucial for solving such calculus problems, as it ties together the physical notion of work with mathematical methods to quantify it.
Integrating to Find Work
To find the total work done when pumping water from the conical tank, we use integration. Integration allows us to add up an infinite number of small amounts of work done in pumping each thin horizontal slice of water up to the desired height. Here, calculus becomes an essential tool as it deals with continuous quantities, unlike summation which is ideal for discrete quantities.

As the depth of the water changes, so does the amount of work needed for each slice鈥攖his variable force requires integrals for an accurate calculation. By integrating the work done over the depth of the tank, we can find the total work required. This approach, called 'integrating to find work', turns a complex real-world problem into a manageable mathematical one.
Volume of a Cone
Understanding the volume of a cone is fundamental in solving our conical tank problem. The volume formula, \( V = \frac{1}{3}\pi r^2h \) where \( r \) and \( h \) are the radius and height of the cone, respectively, lets us determine how much water the tank can hold.

The volume signifies the capacity of our conical tank and is intrinsic to calculating the work done by pumping. A larger volume implies more water, hence more work will be required. Additionally, the concept of volume ties into our integration when we consider each infinitesimally small slice of water at different heights within the tank; we integrate these individual volumes to get the total amount of water we're working with.
Similar Triangles in Calculus
Similar triangles are a powerful tool in calculus, especially when dealing with problems involving variable shapes such as our conical tank. The idea is that if two triangles have the same shape but different sizes, their sides are proportional. We use this property to relate the dimensions of different sections of the tank in our problem.

By setting up a ratio between the sides of the similar triangles formed by the cone's dimensions and the dimensions of the water level at different heights, we can express variables in terms of one another. This relationship is crucial for setting up the integral necessary to find the work done by pumping. It ensures that our variable representing the radius of a horizontal slice of water (and hence the volume of that slice) changes in step with the height of the slice.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Mass of two bars Two bars of length \(L\) have densities \(\rho_{1}(x)=4 e^{-x}\) and \(\rho_{2}(x)=6 e^{-2 x},\) for \(0 \leq x \leq L\) a. For what values of \(L\) is bar 1 heavier than bar \(2 ?\) b. As the lengths of the bars increase, do their masses increase without bound? Explain.

Surface-area-to-volume ratio (SAV) In the design of solid objects (both artificial and natural), the ratio of the surface area to the volume of the object is important. Animals typically generate heat at a rate proportional to their volume and lose heat at a rate proportional to their surface area. Therefore, animals with a low SAV ratio tend to retain heat, whereas animals with a high SAV ratio (such as children and hummingbirds) lose heat relatively quickly. a. What is the SAV ratio of a cube with side lengths \(R ?\) b. What is the SAV ratio of a ball with radius \(R ?\) c. Use the result of Exercise 38 to find the SAV ratio of an ellipsoid whose long axis has length \(2 R \sqrt[3]{4},\) for \(R \geq 1\) and whose other two axes have half the length of the long axis. (This scaling is used so that, for a given value of \(R,\) the volumes of the ellipsoid and the ball of radius \(R\) are equal.) The volume of a general ellipsoid is \(V=\frac{4 \pi}{3} A B C,\) where the axes have lengths \(2 A, 2 B,\) and \(2 C .\) d. Graph the SAV ratio of the ball of radius \(R \geq 1\) as a function of \(R\) (part (b)) and graph the SAV ratio of the ellipsoid described in part (c) on the same set of axes. Which object has the smaller SAV ratio? e. Among all ellipsoids of a fixed volume, which one would you choose for the shape of an animal if the goal were to minimize heat loss?

Water in a bowl A hemispherical bowl of radius 8 inches is filled to a depth of \(h\) inches, where \(0 \leq h \leq 8 .\) Find the volume of water in the bowl as a function of \(h\). (Check the special cases \(h=0 \text { and } h=8 .)\)

Leaky cement bucket A 350 kg-bucket containing \(4650 \mathrm{kg}\) of cement is resting on the ground when a crane begins lifting it at a constant rate of \(5 \mathrm{m} / \mathrm{min.}\) As the crane raises the bucket, cement leaks out of the bucket at a constant rate of \(100 \mathrm{kg} / \mathrm{min.}\) How much work is required to lift the bucket a distance of \(30 \mathrm{m}\) if we ignore the weight of the crane cable attached to the bucket?

Revolution about other axes Let \(R\) be the region bounded by the following curves. Find the volume of the solid generated when \(R\) is revolved about the given line. $$x=2-\sec y, x=2, y=\frac{\pi}{3}, \text { and } y=0 ; \text { about } x=2$$ (IMAGE CAN'T COPY)

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.