# application of integration in chemistry

To find the hydrostatic pressure—that is, the pressure exerted by water on a submerged object—we divide the force by the area. Example $$\PageIndex{6}$$: Finding Hydrostatic Force. A major task in many applications of atmospheric chemistry transport problems is the numerical integration of stiﬀ systems of Ordinary Diﬀerential Equations (ODEs) de-scribing the chemical transformations. =\int ^{540}_{135}62.4 \left(1250−\dfrac{2}{3}x\right)(x−135)\,dx \4pt] Be careful with units. ICT can be applied in chemistry education through its integration into teaching methods, the use of spreadsheets, database, datalogging and in project base learning. Several physical applications of the definite integral are common in engineering and physics. This content by OpenStax is licensed with a CC-BY-SA-NC 4.0 license. wine barrels. \end{align*}, Note the change from pounds to tons ($$2000$$lb = $$1$$ ton) (step 4). We can approximate the volume of a layer by using a disk, then use similar triangles to find the radius of the disk (Figure $$\PageIndex{8}$$). We let $$x$$ represent the vertical distance below the top of the tank. Consumer Surplus. Average value of a function. =−62.4\left(\dfrac{2}{3}\right)\left[\dfrac{x^3}{3}−1005x^2+253125x\right]\bigg|^{540}_{135}≈5,015,230,000\,\text{lb}=2,507,615\,\text{t}. Other applications include the use of radioisotopes to measure (and control) the thickness or density of metal and plastic sheets, to stimulate the cross-linking of polymers, to induce mutations in plants in order to develop hardier species, and to preserve certain kinds of … We look at springs in more detail later in this section. Top 10 blogs in 2020 for remote teaching and learning; Dec. 11, 2020 So, as long as we know the depth, we know the pressure. CHAPTER ONE. So, for $$i=0,1,2,…,n$$, let $$P={x_i}$$ be a regular partition of the interval $$[a,b]$$, and for $$i=1,2,…,n$$, choose an arbitrary point $$x^∗_i∈[x_{i−1},x_i]$$. Statisticianswill use calculus to evaluate survey data to help develop business plans. Area Between 2 Curves. 4.1 Introduction. Figure $$\PageIndex{11}$$ shows the trough and a more detailed view of one end. The limits of integration . Assume a tank in the shape of an inverted cone, with height $$12$$ ft and base radius $$4$$ ft. (Note that if we select a frame of reference other than the one used earlier, we may have to adjust Equation \ref{eqHydrostatic} accordingly. Work can also be calculated from integrating a force function, or when counteracting the force of gravity, as in a pumping problem. Definite integrals can be used to … 4.2: Physical Applications of Integration - Chemistry … Calculate the work done by a variable force acting along a line. To calculate the work done to move an object from point $$x_{i−1}$$ to point $$x_i$$, we assume the force is roughly constant over the interval, and use $$F(x^∗_i)$$ to approximate the force. Many of the same rules for evaluating single integrals apply here, so if you're unfamiliar with those rules, you may want to revie… In pumping problems, the force required to lift the water to the top of the tank is the force required to overcome gravity, so it is equal to the weight of the water. We look at a noncylindrical tank in the next example. Multiply the volume by the weight-density of water to get the force. According to Hooke’s law, the force required to compress or stretch a spring from an equilibrium position is given by $$F(x)=kx$$, for some constant $$k$$. Note that although we depict the rod with some thickness in the figures, for mathematical purposes we assume the rod is thin enough to be treated as a one-dimensional object. Figure $$\PageIndex{6}$$ shows a representative layer. In this section, we examine some physical applications of integration. Select the top of the trough as the point corresponding to $$x=0$$ (step 1). Calculus, all content (2017 edition) Unit: Integration applications. 1. It is often of interest, both in theory and applications, to be able to pass to the limit under the integral. For integration it often contains a product of a function with its derivative like ⁡ ⁡ where integration by substitution is possible. Here is a set of practice problems to accompany the Integration by Parts section of the Applications of Integrals chapter of the notes for Paul Dawkins Calculus II course at Lamar University. Determine the mass of a two-dimensional circular object from its radial density function. Figure $$\PageIndex{2}$$ shows a representative segment of the rod. 2. We see how to use integration to find the centroid of an area with curved sides. ), Determine the depth and width functions, $$s(x)$$ and $$w(x).$$. It should be noted as well that these applications are presented here, as opposed to Calculus I, simply because many of the integrals that arise from these applications tend to require techniques that we discussed in the previous chapter. asked Sep 24 '14 at 18:54. In this case, depth at any point is simply given by $$s(x)=x$$. 1 1 1 4C-5 a) 2πx(1 − x 2 )dx c) 2πxydx = 2πx2dx 0 0 0 a a a b) 2πx(a 2 − x 2 )dx d) 2πxydx = 2πx2 2 1 y = x 1 1 4 We also need to know the distance the water must be lifted. This course is the second of the Calculus series and covers transcendental functions, methods, applications of integration, sequences, and series. We hope this review can help researchers choose suitable methods for their applications using hydrogels. It can be used to find an area bounded, in part, by a curve Areas DEFINITE INTEGRATION AND AREAS Definite integration results in a value. Average Value of a curve can be calculated using integration. First find the spring constant, $$k$$. Both are defined as kilograms times meters squared over seconds squared $$(kg⋅m^2/s^2).$$. \end{align*}\]. 4.4 Application To Chemistry. Taking the limit of this expression as $$n→∞$$ gives us the exact value for work: \begin{align*} W =\lim_{n→∞}\sum_{i=1}^nF(x^∗_i)Δx \\[4pt] =\int ^b_aF(x)dx. That is, we orient the $$x$$-axis vertically, with the origin at the top of the tank and the downward direction being positive (Figure $$\PageIndex{5}$$). Let’s begin with the simple case of a plate of area $$A$$ submerged horizontally in water at a depth s (Figure $$\PageIndex{9}$$). Here is a list of applications that we’ll be taking a look at in this chapter. 5.0 Summary and Conclusion. But just to calculate the concentration of some things, taking care of different kinds of reactants, depending on what you do you'll need to be good in calculus. Mass and momentum of inertia of vehicles 3. Some businesses might custom-build a point-to-point integration. It takes approximately $$33,450$$ ft-lb of work to empty the tank to the desired level. This can also be called integrated process design or process synthesis. We assume the density is given in terms of mass per unit area (called area density), and further assume the density varies only along the disk’s radius (called radial density). Area between a curve and the x-axis. 4. NCERT Solutions for Class 12 Maths – Chapter 8 – Application of Integrals– is designed and prepared by the best teachers across India. Presented to: I-B.Sc Chemistry Then the integral of the solution function should … We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Let $$ρ(x)=3x+2$$ represent the radial density of a disk. \nonumber, Using $$ρ(x^∗_i)$$ to approximate the density of the washer, we approximate the mass of the washer by, Adding up the masses of the washers, we see the mass $$m$$ of the entire disk is approximated by, m=\sum_{i=1}^nm_i≈\sum_{i=1}^n2πx^∗_iρ(x^∗_i)Δx. Derivatives are met in many engineering and … Sometimes this is done symbolically, with equations, but in chemistry it is often done numerically. Use the process from the previous example. Calculus, in general, has a broad applications in diverse fields of science, finance, and business. Let $$ρ(x)=\sqrt{x}$$ represent the radial density of a disk. . What is the force on the face of the dam under these circumstances? Head Injury Criterion is an application of average value and used in road safety research. Note that the area of the washer is given by, \[ \begin{align*} A_i =π(x_i)^2−π(x_{i−1})^2 \\[4pt] =π[x^2_i−x^2_{i−1}] \\[4pt] =π(x_i+x_{i−1})(x_i−x_{i−1}) \\[4pt] =π(x_i+x_{i−1})Δx. The following problem-solving strategy lays out a step-by-step process for solving pumping problems. The mass $$m_i$$ of the segment of the rod from $$x_{i−1}$$ to $$x_i$$ is approximated by, \[ \begin{align*} m_i ≈ρ(x^∗_i)(x_i−x_{i−1}) \\[4pt] =ρ(x^∗_i)Δx. Consider a thin rod oriented on the $$x$$-axis over the interval $$[1,3]$$. Calculate the distance the layer of water must be lifted. For $$i=0,1,2,…,n$$, let $$P={x_i}$$ be a regular partition of the interval $$[0,r]$$, and for $$i=1,2,…,n$$, choose an arbitrary point $$x^∗_i∈[x_{i−1},x_i]$$. To calculate the work done, we partition the interval $$[a,b]$$ and estimate the work done over each subinterval. Several physical applications of the definite integral are common in engineering and physics. Summing the work required to lift all the layers, we get an approximate value of the total work: \[W=\sum_{i=1}^nW_i≈\sum_{i=1}^n62.4πx^∗_i \left(4−\dfrac{x^∗_i}{3}\right)^2\,Δx. Let’s now estimate the force on a representative strip. Mass–Density Formula of a One-Dimensional Object, Given a thin rod oriented along the $$x$$-axis over the interval $$[a,b]$$, let $$ρ(x)$$ denote a linear density function giving the density of the rod at a point $$x$$ in the interval. Definite integrals can be used to determine the mass of an object if its density function is known. There are many applications of integrals, out of which some are mentioned below: In Maths 1. Edward Edward. The plates used in the examples can all be described as regions bounded by one or more curves/lines. a solid obtained by rotating a region bounded by two curves about a vertical or horizontal axis. 25x^2 \right|^{0.5}_0 \\[4pt] =6.25. \end{align*}. Application projects Integration of chemistry and math can be implemented in many di erent ways. The average value of a curve In Physics Integrals are used to calculate 1. With a growing understanding and ability to manipulate chemical molecules, the post-World War II chemist was con-sidered a societal problem solver. The definition of application integration technology can vary by company, depending on the use case, data pattern, and the application integration tools you have on hand, all of which play a big role in how these applications get integrated. The partition divides the plate into several thin, rectangular strips (Figure $$\PageIndex{10}$$). Then, The above is called the second fundamental theorem of calculus. A disk and a representative washer are depicted in the following figure. Adding the forces, we get an estimate for the force on the plate: $F≈\sum_{i=1}^nF_i=\sum_{i=1}^nρ[w(x^∗_i)Δx]s(x^∗_i).$, This is a Riemann sum, so taking the limit gives us the exact force. Suppose a thin plate is submerged in water. As we did in the example with the cylindrical tank, we orient the $$x$$-axis vertically, with the origin at the top of the tank and the downward direction being positive (step 1). application of Differentation& integration in chemistry. . So the pressure is $$p=F/A=ρs$$. Consider a thin rod oriented on the $$x$$-axis over the interval $$[π/2,π]$$. Determine the mass of a one-dimensional object from its linear density function. \tag{step 6}\], \begin{align*} W =\lim_{n→∞}\sum^n_{i=1}62.4πx^∗_i(4−\dfrac{x^∗_i}{3})^2Δx \\[4pt] = \int ^8_062.4πx \left(4−\dfrac{x}{3}\right)^2dx \\[4pt] = 62.4π\int ^8_0x \left(16−\dfrac{8x}{3}+\dfrac{x^2}{9}\right)\,dx=62.4π\int ^8_0 \left(16x−\dfrac{8x^2}{3}+\dfrac{x^3}{9}\right)\,dx \\[4pt] =62.4π\left[8x^2−\dfrac{8x^3}{9}+\dfrac{x^4}{36}\right]\bigg|^8_0=10,649.6π≈33,456.7. Use the process from the previous example. A faster solver that is easier to couple to the 5 other physics in the problem is still needed. . Probability – Many quantities can be described with probability density functions. \end{align*}. Chapter 8: Application of Integrals . Distance, Velocity, Acceleration. Electrochemistry : The Nernst-Plank equation is challenging. Although in the real world we would have to account for the force of friction between the block and the surface on which it is resting, we ignore friction here and assume the block is resting on a frictionless surface. It is rare, however, for a force to be constant. This expression is an estimate of the work required to pump out the desired amount of water, and it is in the form of a Riemann sum. As we did there, we use $$x^∗_i≈(x_i+x_{i−1})/2$$ to approximate the average radius of the washer. Therefore, we partition the interval $$[2,10]$$ and look at the work required to lift each individual “layer” of water. Contributors and Attributions. If the density of the rod is given by $$ρ(x)=2x^2+3,$$ what is the mass of the rod? Derivatives in Physics • In physics, the derivative of the displacement of a moving body with respect to time is the velocity of the body, and the derivative of velocity W.R.T time is acceleration. Assume the top edge of the plate is at point $$x=a$$ and the bottom edge of the plate is at point $$x=b$$. In this state, the spring is neither elongated nor compressed, and in this equilibrium position the block does not move until some force is introduced. We state this result in the following theorem. Note we often let $$x=0$$ correspond to the surface of the water. Select a frame of reference with the $$x$$-axis oriented vertically and the downward direction being positive. share | improve this question | follow | edited Oct 15 '17 at 13:10. We summarize this in the following problem-solving strategy. Now it has spread its applications into wider fields like engineering, physics, surveying, architecture, astronomy and even in the investigation of a crime scene. Practice. Differentiation and integration can help us solve many types of real-world problems. The water exerts a force of 748.8 lb on the end of the trough (step 4). \nonumber\], We again recognize this as a Riemann sum, and take the limit as $$n→∞.$$ This gives us, \begin{align*} m =\lim_{n→∞}\sum_{i=1}^n2πx^∗_iρ(x^∗_i)Δx \\[4pt] =\int ^r_02πxρ(x)dx. We obtain, \[A_i=π(x_i+x_{i−1})Δx≈2πx^∗_iΔx. All the important topics are covered in the exercises and each answer comes with a detailed explanation to help students understand concepts better. Applications integration (or enterprise application integration) is the sharing of processes and data among different applications in an enterprise. Application of Radioactivity. Suppose it takes a force of $$8$$ lb to stretch a spring $$6$$ in. We then turn our attention to work, and close the section with a study of hydrostatic force. Application integration is the process of enabling individual applications—each designed for its own specific purpose—to work with one another. Then the work to lift the $$i^{\text{th}}$$ layer of water $$W_i$$ is approximately, Adding the work for each layer, we see the approximate work to empty the tank is given by, \[ \begin{align*} W =\sum_{i=1}^nW_i \\[4pt] ≈\sum_{i=1}^n156,800πx^∗_iΔx.\end{align*}, This is a Riemann sum, so taking the limit as $$n→∞,$$ we get, \begin{align*} W =\lim_{n→∞}\sum^n_{i=1}156,800πx^∗_iΔx \\[4pt] = 156,800π\int ^{10}_2xdx \\[4pt] =156,800π \left( \dfrac{x^2}{2}\right)\bigg|^{10}_2=7,526,400π≈23,644,883. \tag{step 5}. If the density of the rod is not constant, however, the problem becomes a little more challenging. The upper limit remains $$540$$. The work done over the interval $$[x_{i−1},x_i]$$, then, is given by, $W_i≈F(x^∗_i)(x_{i}−x_{i−1})=F(x^∗_i)Δx.$, Therefore, the work done over the interval $$[a,b]$$ is approximately, $W=\sum_{i=1}^nW_i≈\sum_{i=1}^nF(x^∗_i)Δx.$. Definite integrals can be used to … Definite integrals can be used to … 4.2: Physical Applications of Integration - Chemistry LibreTexts 5.2 Conclusion. Enterprise Application Integration (EAI) is an important factor in the success of the enterprise application as standalone applications cannot contribute to the success of the increasing business demand of today. Advanced topics and the outlook of hydrogel fabrication and applications are also discussed. How to increase brand awareness through consistency; Dec. 11, 2020. In mainstream economics, economic surplus (also known as total welfare or Marshallian surplus) refers to two related quantities. 4.2: Physical Applications of Integration, [ "article:topic", "work", "hydrostatic pressure", "showtoc:no", "license:ccbyncsa", "transcluded:yes", "density function", "Hooke\u2019s law", "radial density", "source-math-2523", "authorname:openstaxstrang" ], 4.1: Volumes of Revolution - Cylindrical Shells, information contact us at info@libretexts.org, status page at https://status.libretexts.org. In this section we’re going to take a look at some of the Applications of Integrals. Applications of Derivatives in Various fields/Sciences: Such as in: –Physics –Biology –Economics –Chemistry –Mathematics –Others(Psychology, sociology & geology) 15. Unit: Integration applications. We use integration to find the force. Here, we systematically review the physical properties of hydrogels, general methods for gel–microfluidics integration and applications of this field. According to physics, when we have a constant force, work can be expressed as the product of force and distance. We use the derivative to determine the maximum and minimum values of particular functions (e.g. Dept. What is considered here is to bring more examples of applications from chem-istry into the math courses, for motivation and better understanding, and to incorporate more math into the chemistry courses to reach a higher level. Some applications of chemistry. In integral calculus, integration by reduction formulae is method relying on recurrence relations. 2. Credit card companiesuse calculus to set the minimum payments due on credit card statements at the exact time the statement is processed. =\int ^{540}_{10}62.4 \left(1250−\dfrac{2}{3}x\right)(x−10)\,dx \4pt] Use the equation to calculate the total force. In this atom, we will see some examples of applications of integration in economics and biology. The LibreTexts libraries are Powered by MindTouch® and are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. \nonumber \end{align*}. Applications of integration E. Solutions to 18.01 Exercises b b h) 2πyxdy = 2πy(a 2 (1 − y 2/b2)dy 0 0 (Why is the lower limit of integration 0 rather than −b?) Area between curves. Thus, Using a weight-density of $$62.4$$lb/ft3 (step 3) and applying Equation \ref{eqHydrostatic}, we get, \begin{align*} F =\int^b_a ρw(x)s(x)\,dx \\[4pt] 4. We now consider work. The southwest United States has been experiencing a drought, and the surface of Lake Mead is about 125 ft below where it would be if the reservoir were full. Definite integrals can also be used to calculate the force exerted on an object submerged in a liquid. The work done to compress (or elongate) a spring, for example, varies depending on how far the spring has already been compressed (or stretched). Now, for $$i=0,1,2,…,n$$ let $$P={x_i}$$ be a regular partition of the interval $$[a,b]$$, and for $$i=1,2,…,n$$ choose an arbitrary point $$x^∗_i∈[x_{i−1},x_i]$$. \end{align*}. give the boundaries of the area. 3. 1. It should be noted as well that these applications are presented here, as opposed to Calculus I, simply because many of the integrals that arise from these applications tend to require techniques that we discussed in the previous chapter. Analytical Standard Operations and Applications. Section 7.8 Economics Applications of the Integral. Based on our choice of coordinate systems, we can use $$x^∗_i$$ as an approximation of the distance the layer must be lifted. DOI: 10.1021/ac020239t. Evaluating the integral, we get, \begin{align*} F =\int^b_aρw(x)s(x)\,dx \\[4pt] Then the mass of the rod is given by. First we consider a thin rod or wire. The tank is depicted in Figure $$\PageIndex{7}$$. Mass and momentum of a tower 5. Adding the masses of all the segments gives us an approximation for the mass of the entire rod: \[ \begin{align*} m =\sum_{i=1}^nm_i \\[4pt] ≈\sum_{i=1}^nρ(x^∗_i)Δx. Integration gives the relative number of hydrogens present at each signal; The integrated intensity of a signal in a 1 H NMR spectrum (does not apply to 13 C NMR) gives a ratio for the number of hydrogens that give rise to the signal, thereby helping calculate the total number of hydrogens present in a sample. We choose our frame of reference such that the $$x$$-axis is oriented vertically, with the downward direction being positive, and point $$x=0$$ corresponding to a logical reference point. Hydrostatic Pressure and Force – In this section we’ll determine the hydrostatic pressure and force on a vertical plate submerged in water. Example $$\PageIndex{3}$$: The Work Required to Stretch or Compress a Spring. Extending this idea to the realm of calculus integration, the single integral (which uses one variable) becomes the double integral(which uses two variables). Evaluating this integral gives us the force on the plate. Now let’s look at the specific example of the work done to compress or elongate a spring. 4.0 Applications of differentiation. In this last section, we look at the force and pressure exerted on an object submerged in a liquid. This same unit is also called the joule. Calculus (differentiation and integration) was developed to improve this understanding. Arc Length – In this section we’ll determine the length of a curve over a given interval. Radioisotopes find numerous applications in a variety of areas such as medicine, agriculture, biology, chemistry, archeology, engineering and industry. Watch the recordings here on Youtube! Process integration is a term in chemical engineering which has two possible meanings.. A holistic approach to process design which emphasizes the unity of the process and considers the interactions between different unit operations from the outset, rather than optimising them separately. ). This changes our depth function, $$s(x)$$, and our limits of integration. Find the hydrostatic force against a submerged vertical plate. Because density is a function of $$x$$, we partition the interval from $$[0,r]$$ along the $$x$$-axis. Have questions or comments? We write Using properties of similar triangles, we get $$r=250−(1/3)x$$. We have introduced the Semantic Web concepts, technologies, and methodologies that can be used to support chemistry research, and have demonstrated the application of those techniques in three areas very relevant to modern chemistry research, generating three new datasets that we offer as exemplars of an extensible portfolio of advanced data integration facilities. Example $$\PageIndex{4}$$: A Pumping Problem with a Noncylindrical Tank. Orient the rod so it aligns with the $$x$$-axis, with the left end of the rod at $$x=a$$ and the right end of the rod at $$x=b$$ (Figure $$\PageIndex{1}$$). Problem-Solving Strategy: Finding Hydrostatic Force, Example $$\PageIndex{5}$$: Finding Hydrostatic Force. We now apply this problem-solving strategy in an example with a noncylindrical tank. Integration gives the relative number of hydrogens present at each signal The integrated intensity of a signal in a 1 H NMR spectrum (does not apply to 13 C NMR) gives a ratio for the number of hydrogens that give rise to the signal, thereby helping calculate the total number of … Centre of gravity 2. Calculate the mass of a disk of radius 4. \end{align*}, You may recall that we had an expression similar to this when we were computing volumes by shells. In addition, instead of being concerned about the work done to move a single mass, we are looking at the work done to move a volume of water, and it takes more work to move the water from the bottom of the tank than it does to move the water from the top of the tank. Approximately 7,164,520,000 lb or 3,582,260 t. Gilbert Strang (MIT) and Edwin “Jed” Herman (Harvey Mudd) with many contributing authors. applications of integration Definition Integration is a method of summing up physical quantities under the limiting case of infinitesimal differential change in the quantity. Now, use the partition to break up the disk into thin (two-dimensional) washers. The need for application integration usually arises when a company adopts a new software application to improve or replace an outdated business process. In physics, work is related to force, which is often intuitively defined as a push or pull on an object. The constant $$k$$ is called the spring constant and is always positive. A tank is in the shape of an inverted cone, with height $$10$$ ft and base radius 6 ft. physical-chemistry kinetics. The module outlines a programme of objectives and related activities for an ICT-. Applications of Derivatives in Various fields/Sciences: Such as in: –Physics –Biology –Economics –Chemistry –Mathematics –Others(Psychology, sociology & geology) 15. Note that if $$F$$ is constant, the integral evaluates to $$F⋅(b−a)=F⋅d,$$ which is the formula we stated at the beginning of this section. Chapter 8: Application of Integrals . cost, strength, amount of material used in a building, profit, loss, etc.). The actual dam is arched, rather than flat, but we are going to make some simplifying assumptions to help us with the calculations. When the density of the rod varies from point to point, we use a linear density function, $$ρ(x)$$, to denote the density of the rod at any point, $$x$$. A water trough 15 ft long has ends shaped like inverted isosceles triangles, with base 8 ft and height 3 ft. Find the force on one end of the trough if the trough is full of water. It is used for Portfolio Optimization i.e., how to choose the best stocks. Integration. Integration of immobilized trypsin bead beds for protein digestion within a microfluidic chip incorporating capillary electrophoresis separations and an electrospray mass spectrometry interface. We apply this theorem in the next example. In this section we’re going to take a look at some of the Applications of Integrals. We have thereby … How much work is done to stretch the spring $$1$$ ft from the equilibrium position? Several physical applications of the definite integral are common in engineering and physics. To find the area under a curve 4. The new application is desirable for its efficiency, but problems arise during implementation because the new software must interoperate—usually in both upstream and downstream processes—with legacy applications. \tag{step 2}\], The weight-density of water is $$62.4$$lb/ft3, so the force needed to lift each layer is approximately, $F_i≈62.4π\left(4−\dfrac{x^∗_i}{3}\right)^2\,Δx \tag{step 3}$, Based on the diagram, the distance the water must be lifted is approximately $$x^∗_i$$ feet (step 4), so the approximate work needed to lift the layer is, \[W_i≈62.4πx^∗_i\left(4−\dfrac{x^∗_i}{3}\right)^2\,Δx. If the density of the rod is given by $$ρ(x)=\sin x$$, what is the mass of the rod? the question of practical applications of integrations in daily life. Sketch a picture and select an appropriate frame of reference. Remember that integration ratios are really only meaningful within a single compound.