问题1.考虑一个帐篷,其形状为圆柱形,并由高度为16 m和半径的圆锥形顶部覆盖,该顶部对于构成该帐篷整个部分的等于24 m的所有表面都是相同的。帐篷的圆柱部分的高度为11 m。找到帐篷所需的画布区域。
解决方案:
According to the question
Diameter of the cylinder = 24 m,
So the radius(r) = 24/2 = 12 m,
Height of the cylindrical part (H1) = 11m
and the total height of the shape = 16 m
So, the height of the cone (h)= 16 – 11 = 5m
Now, first we find the slant height of the cone
So, according to the formula of slant height
l = √r2 + h2
l = √122 + 52 = 13m
Now, we find the curved surface area of the cone
A1 = πrl
= 22/7 × 6 × 13 ……(1)
Now, we find the curved surface area of the cylinder
A2 = 2πrH1
= 2π(12)(11) ……(2)
Now we find the total area of canvas required for tent,
So,
A = A1 + A2
= 22/7 × 12 × 13 + 2 × 22/7 × 12 × 11
= 490 + 829.38 = 1319.8 = 1320 m2
Hence, the total canvas required for tent is 1320 m2
问题2.考虑一个火箭。假设火箭在下端为封闭的圆柱体形式,其顶部连接有相同半径的圆锥体。火箭的圆柱部分的半径为2.5 m,而火箭的圆柱部分的高度为21m。火箭的圆锥形部分的倾斜高度为8m,然后计算火箭的总表面积并找到火箭的体积。
解决方案:
According to the question
Radius of the cylindrical part of the rocket(r) = 2.5 m,
Height of the cylindrical part of the rocket (h) = 21 m,
Slant Height of the conical surface of the rocket(l) = 8 m,
Now, we find the curved surface area of the cone
A1 = πrl
= π(2.5)(8)
= π x 20 ……(1)
Now, we find the curved surface area of the cone
A2 = 2πrh + πr2
= (2π × 2.5 × 21) + π (2.5)2
= (π × 10.5) + (π × 6.25) ……(2)
Now we find the total curved surface area
A = A1 + A2
= (π x 20) + (π x 10.5) + (π x 6.25)
= 62.83 + 329.86 + 19.63 = 412.3 m2
Hence, the total curved surface area of the conical surface is 412.3 m2
Let us considered H be the height of the conical portion in the rocket,
So, l2 = r2 + H2
H2 = l2 – r2
h = √82 – 2.52 = 23.685 m
Now we find the volume of the conical surface of the rocket
V1 = 1/3πr2H
= 1/3 × 22/7 × (2.5)2 × 23.685 ……(3)
Now we find the volume of the cylindrical part
V2 = πr2h
V2 = 22/7 × 2.52 × 21
Therefore, the total volume of the rocket
V = V1 + V2
V = 461.84 m2
Hence, the total volume of the Rocket is 461.84 m2
问题3.视线中的帐篷结构为圆柱形,高度为77 dm,顶部为圆锥形,顶部高度为44 dm。圆柱体的直径为36 m。找到帐篷的曲面区域。
解决方案:
According to the question
Height of the tent = 77 dm,
Height of a surmounted cone = 44 dm,
Diameter of the cylinder = 36 m,
So, the radius of the cylinder(r) = 36/2 = 18 m
Therefore, the height of the cylindrical Portion(h) = 77 – 44 = 33 dm = 3.3 m
Let us considered l be the slant height of the cone,
So,l2 = r2 + h2
l2 = 182 + 3.32
l2 = 324 + 10.89 = 334.89 = 18.3 m
Now we find the curved surface area of the cylinder
A1 = 2πrh
= 2π184.4 m2 ……(1)
Now we find the curved surface area of the cone
A2 = πrh
= π × 18 × 18.3 ……(2)
Hence, the total curved surface of the tent
A = A1 + A2
Put all the values from eq(1) and (2)
A = (2π x 18 × 4.4) + (π x 18 × 18.3) = 1532. 46 m2
Hence, the total Curved Surface Area is 1532.46 m2
问题4:玩具是圆锥形的,悬在半球上。底座的直径和圆锥体的高度分别为6厘米和4厘米。确定玩具的表面积。
解决方案:
According to the question
The height of the cone (h) = 4 cm
Diameter of the cone (d) = 6 cm,
So, radius of the cone (r) = 3
Also radius of the cone = radius of the hemisphere.
Let us considered l be the slant height of the cone,
l = √r2 + h2
l = √32 + 42 = 5 cm
Now we find the curved surface area of the cone
A1 = πrl
= π(3)(5) = 47.1 cm2
Now we find the curved surface area of the hemisphere
A1 = 2πr2
= 2π(3)2 = 56.23 cm2
Hence, the total surface area of toy
A = A1 + A2
= 47.1 + 56.23 = 103.62 cm2
Hence, the curved surface area of the toy is 103.62 cm2
问题5.固体为直圆柱体形式,一端为半球,另一端为圆锥。公共基座的半径为3.5厘米,圆柱和圆锥形部分的高度分别为10厘米和6厘米。找到固体的总表面积。 (使用π= 22/7)。
解决方案:
According to the question
The radius of the common base (r) = 3.5 cm,
Height of the cylindrical part (h) = 10 cm,
Height of the conical part (h1) = 6 cm
Let us considered l be the slant height of the cone,
So,
l = √r2 + h2 = √3.52 + 62 = 48.25 cm
Now we find the curved surface area of the cone
A1 = πrl
= π(3.5)(48.25) = 76.408 cm2
Now we find the curved surface area of the hemisphere
A2 = 2πrh
= 2π(3.5) (10) = 220 cm2
Therefore, the total surface area of the solid
A = A1 + A2
= 76.408 + 220 = 373.408 cm2
Hence, total surface area of the solid is 373.408 cm2.
问题6.玩具的形状为直角圆柱,一端为半球形,另一端为圆锥形。圆柱部分的半径和高度分别为5厘米和13厘米。半球形和圆锥形部分的半径与圆柱部分的半径相同。如果玩具的总高度为30厘米,请找到玩具的表面积。
解决方案:
According to the question
The height of the cylindrical part(h1) = 13 cm,
Radius of the cylindrical part(r) = 5 cm,
Height of the whole solid(H) = 30 cm,
The height of the conical part,
h2 = 30 – 13 – 5 = 12 cm
Now we find the slant height of the cone
l = √r2 + h22 = √52 + 122 = 13 cm
Now we find the curved surface area of the cylinder
A1 = 2πrh1
= 2π(5)(13) = 408.2 cm2
Now we find the curved surface area of the cone
A2 = πrl
= π(5)(13) cm2 = 204.1 cm2
Now we find the curved surface area of the hemisphere
A3 = 2πr2
= 2π(5)2 = 157 cm2
Hence, the total curved surface area of the toy
A = A1 + A2 + A3
= (408.2 + 204.1 + 157) = 769.3 cm2
Hence, the surface area of the toy is 769.3 cm2
问题7.考虑一个半径为5厘米,长度为9.8厘米的圆柱桶。到处都是水。将安装在半球上的呈直角圆锥体形式的固体浸入桶中。如果半球的半径为3.5厘米,并且半球外侧的圆锥体的高度为5厘米。找到浴缸中剩余的水量。
解决方案:
According to the question
Radius of the Cylindrical tub(r) = 5 cm,
Height of the Cylindrical tub(h1) = 9.8 cm,
Height of the cone outside the hemisphere (h2) = 5 cm,
Radius of the hemisphere = 5 cm.
Now we find the volume of the cylindrical tub
V1 = πr2h1
= π(5)2 9.8 = 770 cm3
Now we find the volume of the Hemisphere
V2 = 2/3 × π × r3
= 2/3 × 22/7 × 3.53 = 89.79 cm3
Now we find the volume of the cone
V3= 1/3 × π × r2 × h2
= 1/3 × 22/7 × 3.52 × 5 = 64.14 cm3
Hence, The total volume
V = V2 + V3
V = 89.79 + 64.14 = 154 cm3
Hence, the total volume of the solid = 154 cm3
Hence, the volume of water left in the tube V = V1 – V2
V = 770 – 154 = 616 cm3
Hence, the volume of water left in the tube is 616 cm3.
问题8.马戏团的帐篷是圆柱形的,上面是圆锥形的屋顶。圆柱形底座的半径为20厘米。圆柱和圆锥形部分的高度分别为4.2厘米和2.1厘米。找到马戏团帐篷的体积。
解决方案:
According to the question
Radius of the cylindrical part(R) = 20 m,
Height of the cylindrical part(h1) = 4.2 m,
Height of the conical part(h2) = 2.1 m,
Now we find the volume of the cylindrical part
V1 = πr2 h1
= π(20)2 4.2 = 5280 m3
Now we find the volume of the conical part
V2 = 1/3 × π × r2 × h2
= 1/3 × 22/7 × r2 × h2
= 13 × 22/7 × 202 × 2.1 = 880 m3
Hence, the total volume of the circus tent
V = V1 + V2 = 6160 m3
Hence, the volume of the circus tent is 6160 m3
问题9.汽油箱是一个底直径为21厘米,长为18厘米,并带有圆锥形末端的圆柱体,每个圆锥形末端的轴线均为9厘米。确定水箱的容量。
解决方案:
According to the question
Base diameter of the cylinder = 21 cm,
Radius (r) = diameter/2 = 25/2 = 11.5 cm,
Height of the cylindrical part of the tank (h1) = 18 cm,
Height of the conical part of the tank (h2) = 9 cm.
Now we find the volume of the cylindrical portion
V1 = πr2 h1
= π(11.5)2 18 = 7474.77 cm3
Now we find the volume of the conical portion
V2 = 1/3 × 22/7 × r2 × h2
= 1/3 × 22/7 × 11.52 × 9 = 1245.795 cm3
Hence, the total the capacity of the tank
V = V1 + V2
= 7474.77 + 1245.795
= 8316 cm3
Hence, the capacity of the tank is 8316 cm3
问题10.在高度为12 cm,底半径为5 cm的圆柱体上钻一个圆锥孔。圆锥体的高度和基本半径也相同。找到剩余圆柱体的整个表面和体积。
解决方案:
According to the question
Height of the cone = Height of the cylinder = h = 12 cm,
Radius of the cone = Radius of the cylinder = r = 5 cm.
Let us considered l be the slant height of the cone
So,
l = √r2 + h2 = √52 + 122 = 13 cm
Now we find the total surface area of the remaining part in the circular cylinder
A= πr2 + 2πrh + πrl
= π(5)2 + 2π(5)(12) + π(5)(13) = 210 π cm2
Now we find the volume of the remaining part of the circular cylinder
V = πr2h – 1/3 πr2h
= πr2h – 1/3 × 22/7 × r2 × h
= π(5)2(12) – 1/3 × 22/7 × 52 × 12 = 200 π cm2
Hence, the area of the remaining part is 210 π cm2 and the volume is 200 π cm2
问题11:帐篷的形式为直径为20 m,高度为2.5 m的圆柱体,并由等底高为7.5 m的圆锥体覆盖。以100卢比/平方米的价格查找帐篷的容量和画布的成本。
解决方案:
According to the question
Diameter of the cylinder = 20 m,
So, the radius of the cylinder = 10 m,
Height of the cylinder (h1) = 2.5 m,
Radius of the cone = Radius of the cylinder = r = 15 m,
Height of the Cone (h2) = 7.5 m.
Let us considered l be the slant height of the cone
So,
l = √r2 + h22 = √152 + 7.52 = 12.5 m
Now we find the volume of the cylinder
V1 = πr2h1
= π(10)2 2.5 = 250π m3
Now we find the volume of the Cone
V2 = 1/3πr2h2
= 1/3 × 22/7 × 102 × 7.5 = 250π m3
Hence, the total capacity of the tent
V = V1 + V2
= 250 π + 250 π = 500π m3
Hence, the total capacity of the tent = V = 4478.5714 m3
Now we find the total area of the canvas required for the tent is
S = 2πrh1 + πrl
= 2(π)(10)(2.5) + π(10)(12.5) = 550 m2
Hence, the total cost of the canvas is (100 x 550) = Rs. 55000
问题12.考虑一个锅炉,该锅炉为长2 m的圆柱体形式,并且有一个半球形的端部,每个端部的直径为2 m。查找锅炉的体积。
解决方案:
According to the question
Diameter of the hemisphere = 2 m,
So, the radius of the hemisphere (r) = 1 m,
Height of the cylinder (h) = 2 m,
Now we find the volume of the cylinder
V1 = πr2h
= π(1)2 x 2 = 22/7 × 2 = 44/7m3
Since, at each of the ends of the cylinder, two hemispheres are attached.
so, the volume of two hemispheres
V2 = 2 × 2/3πr3
= 2 × 2/3 × 22/7 × 13 = 22/7 × 4/3 = 88/21 m3
Hence, the volume of the boiler is
V = V1 + V2
V = 44/7 + 88/21 = 220/21 m3
Hence, the volume of the boiler is 220/21 m3