5.7
ジェット機の翼に搭載された燃料タンクの体積は、回転体を用いてモデル化できます。この場合、タンクは、数学関数で定義された2次元領域をx軸のまわりに回転させることによって形成されます。この領域は軸に沿って0 mから2 mまで広がり、結果として得られる3次元形状は回転軸に対して対称です。境界曲線が回転軸に…
ジェット機の翼に取り付けられた燃料タンクは、中心軸を中心に回転する領域によって形成されます。この領域は、x軸を中心に数学関数を回転させることで形成され、0メートルから2メートルまで広がります。
タンクの体積を求めるにはディスク法が用いられ、これは固体をx軸に垂直な無限細い円盤に切り分けます。
各円盤の面積は ��(関数の値の二乗)に等しいです。これらの領域を区間内で積分することで、総体積を求めます。
関数を二乗すると、積分子は定数にxの2乗と2とxの差を掛けたものに簡略化されます。
この式を展開・積分すると、xの3乗と4乗を含む反微分が得られます。
0から2までの定積分を評価し、極限を代入すると式が得られます。さらに簡略化すると、燃料タンクの総体積である約1立方メートルの体積が得られます。
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Q1: What is the disk method and how does it apply to finding volume?
The disk method divides a solid of revolution into infinitesimally thin circular disks perpendicular to the axis of rotation. Each disk's area equals π times the square of the function's radius value. By integrating these disk areas over the specified interval, you accumulate the total volume of the solid using calculation of volume of solids by integration.
Q2: How is a fuel tank modeled as a solid of revolution?
A fuel tank is modeled by rotating a two-dimensional region defined by a mathematical function about the x-axis. The region extends from zero to two meters along the axis, creating a three-dimensional symmetric shape. This approach allows engineers to calculate precise fuel capacity and weight distribution for aircraft performance.
Q3: What steps are involved in calculating the volume using integration?
First, square the function defining the tank's boundary to get the disk area formula. Then expand the resulting expression to identify terms with third and fourth powers of the variable. Finally, integrate these terms over the interval from zero to two meters and evaluate the definite integral by substituting the limits.
Q4: Why is the disk method appropriate for this fuel tank problem?
The disk method is appropriate because the boundary curve lies directly against the axis of rotation, creating circular cross-sections perpendicular to the x-axis. This geometry allows each disk's radius to equal the function value at that position, making the method straightforward and accurate for calculating the tank's volume.
Q5: What does the antiderivative represent in this volume calculation?
The antiderivative describes how volume accumulates along the axis of integration as you move from zero to two meters. It captures the cumulative effect of all infinitesimal disk areas stacked along the tank's length. Evaluating this antiderivative at the limits yields the total internal capacity of approximately one cubic meter.
Q6: How does the definite integral produce the final volume result?
The definite integral evaluates the antiderivative at the upper limit of two meters and subtracts its value at the lower limit of zero. This calculation yields a numerical result that simplifies to approximately one cubic meter, representing the total fuel tank capacity needed for aerospace engineering applications.
Q7: Why is precise volume calculation critical in aerospace engineering?
Accurate volume estimates determine fuel capacity, weight distribution, and overall aircraft performance. Engineers must know exact tank dimensions to optimize fuel storage, balance aircraft weight, and ensure safe flight operations. Mathematical modeling through integration provides the precision necessary for reliable aerospace design and safety.