A tank in the shape of a hemisphere with a radius r = 13 ft is full of water to a depth of 11 ft. Set up the integral that would find the work W required to pump the water out of the spout. Use the location of the origin and the direction of the positive axis as specified in the different parts. hemisphere

Note: Use 62.5 lb/ft^3 as the weight of water.
a. The origin is at the top of the tank with positive y variables going down.
b. The origin is at the bottom of the tank with positive y-values going up.

Respuesta :

Answer:

(a). The integral is [tex]W=62.5\pi\int_{0}^{11}(169-y^2)ydy[/tex]

(b). The integral is [tex]W=62.5\pi\int_{0}^{11}{48+22y-y^2(11-y)}dy[/tex]

Step-by-step explanation:

Given that,

Radius = 13 ft

Depth = 11 ft

Weight of water = 62.5 lb/ft³

(a). The origin is at the top of the tank with positive y variables going down.

We need to calculate the volume of the strip

Using formula of volume

[tex]dV=\pi r^2dy[/tex]

Put the value into the formula

[tex]dV=\pi(\sqrt{13^2-y^2})^2dy[/tex]

[tex]dV=\pi({169-y^2})dy[/tex]

We need to calculate the mass of the strip

Using formula of mass

[tex]W=\rho dVgy[/tex]

Put the value into the formula

[tex]W=\pi({169-y^2})dy\times62.5\ y[/tex]

We need to calculate the work done to pump the water out of the spout

Using formula of work done

[tex]W= \int_{0}^{11}(\pi({169-y^2})dy\times62.5\ y)[/tex]

[tex]W=62.5\pi\int_{0}^{11}(169-y^2)ydy[/tex]

(b). The origin is at the bottom of the tank with positive y-values going up

We need to calculate the volume of the strip

Using formula of volume

[tex]dV=\pi r^2dy[/tex]

Put the value into the formula

[tex]dV=\pi(\sqrt{13^2-(11-y)^2})^2dy[/tex]

[tex]dV=\pi(169-(121-22y+y^2))dy[/tex]

[tex]dV=\pi(169-121+22y-y^2)dy[/tex]

[tex]dV=\pi(48+22y-y^2)dy[/tex]

We need to calculate the mass of the strip

Using formula of mass

[tex]W=\rho Vg[/tex]

Put the value into the formula

[tex]W=dV\rho g(11-y)[/tex]

[tex]W=\pi(48+22y-y^2)dy\rho g(11-y)[/tex]

[tex]W=62.5\pi(48+22y-y^2)(11-y)dy[/tex]

We need to calculate the work done to pump the water out of the spout

Using formula of work done

[tex]W=\int_{0}^{11}{62.5\pi(48+22y-y^2)(11-y)dy}[/tex]

[tex]W=62.5\pi\int_{0}^{11}{48+22y-y^2(11-y)}dy[/tex]

Hence, (a). The integral is [tex]W=62.5\pi\int_{0}^{11}(169-y^2)ydy[/tex]

(b). The integral is [tex]W=62.5\pi\int_{0}^{11}{48+22y-y^2(11-y)}dy[/tex]

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