Find the volume and surface area of the following solid:

A Hemisphere attached on top of a cylinder.
I'm not sure if the picture resolution is clear for everyone to see and understand, so I'll describe its properties as well:

Hemisphere 's radius=7cm
Cylinder's height= 10cm
Cylinder 's radius= 7cm
Total height of the solid= 17cm

Please help me out with this question. I am in dire need of the answer, as my finals are nearing.
If there is any confusion with the question, please ask me. I'll be glad to elaborate.
Thank you.​

Find the volume and surface area of the following solidA Hemisphere attached on top of a cylinderIm not sure if the picture resolution is clear for everyone to class=

Respuesta :

Step-by-step explanation:

Here,

radius of hemisphere and cylinder(r)=7 cm

height of the cylinder(h)= 10 cm

Now the volume of cylinder(V1) is,

[tex]\pi {r}^{2} h \\ = \pi \times {7}^{2} \times 10 \\ = 1540 \: {cm}^{3} \\ [/tex]

And the volume of hemisphere(V2) is,

[tex] \frac{2}{3} \pi {r}^{3} = \frac{2}{3} \times \pi \times {7}^{3} \\ = 718.67 \: {cm}^{3} [/tex]

Total volume=V1+V2=1540+718.67= 2258.67 cu.cm

Surface area of cylinder(A2)=

[tex]2\pi \: rh + 2\pi {r}^{2} = 2\pi \: r(h + r) \\ = 2 \times \pi \times 7 \times (10 + 7) \\ = 44 \times 17 \\ = 748 \: {cm}^{2} [/tex]

Surface area of hemisphere(A2)=

[tex]2\pi {r}^{2} = 2 \times \pi \times {7}^{2} = 308 \: {cm}^{2} [/tex]

Then total Surface area=A1+A2

=748+308=1056 sq.cm

1. First, let us find the volume. Now the total volume is simply given by adding the volume of the cylinder to that of the hemisphere.

Let us revisit the formulas for the volume of a cylinder and hemisphere.

Cylinder: V = πr^(2)h

Hemisphere: V = (2/3)πr^3

Thus, the total volume is given by πr^(2)h + (2/3)πr^3

Using the values provided in the diagram, we can now say that:

Total volume = π(7)^(2)*10 + (2/3)π(7)^3

= 490π + 686π/3

= 2156π/3 cm cubed

Using π = 22/7, we can now see that:

Total volume = 2156*(22/7) / 3

= 2258.67 cm cubed (to two decimal places)

2. Now let's find the total surface area. Let's review the formulas for total surface area for a cylinder and a hemisphere:

Cylinder: SA = 2πr^2 + 2πrh (this is the area of the top and bottom, plus the area of the rectangle that is wrapped around)

However, since the top of the cylinder is covered by the hemisphere, we don't need to count its area in the surface area, thus we must use SA = πr^2 + 2πrh

Hemisphere: SA = πr^2 + 2πr^2 = 3πr^2 (this is the area of the bottom of the hemisphere plus the area of half of the sphere)

However, since the bottom of the hemisphere is on the cylinder, we don't count this in the total surface area either, therefor we must use SA = 2πr^2

Thus, total surface area is given by:

πr^2 + 2πrh + 2πr^2

= 3πr^2 + 2πrh

Now we can substitute the values of the radius and cylinder height into the formula above. So:

TSA = 3πr^2 + 2πrh

TSA = 3π(7)^2 + 2π(7)(10)

= 147π + 140π

= 287π cm squared

Using π = 22/7, we can now see that:

TSA = 287*(22/7)

= 902 cm squared