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To make a conical funnel, its generatrix length is 20 cm, and its height should be () cm A. 2033B. 100C. 20D. 203
Let the height of cone be x, then the bottom radius is 202 − X2, and its volume is v = 13 π x (202-x2) (0 ＜ x ＜ 20), V ′ = 13 π (400-3x2). Let V ′ = 0, then the solution is X1 = 2033, X2 = - 2033 (rounding off). When 0 ＜ x ＜ 2033, V ′＞ 0; when 2033 ＜ x ＜ 20, V ′＜ 0; when x = 2033, V takes the maximum value
To make a conical funnel, its generatrix is 20 cm, and to make its volume the largest, what is its height?
If you want to make a 144m ^ 3 open rectangular box with a square bottom, if the cost per unit area is 4 yuan for the bottom and 3 yuan for the side area, how can you save the cost most.
If the side length of the bottom is x, then the height is 144 / x ^ 2; if the cost is y, then the equation y = 4x ^ 2 + (4 * x) * (144 / x ^ 2) * 3 can be formulated and solved
To make a conical funnel, its generatrix length is 20 cm, and its height should be () cm
A. 2033B. 100C. 20D. 203
Let the height of cone be x, then the bottom radius is 202 − X2, and its volume is v = 13 π x (202-x2) (0 ＜ x ＜ 20), V ′ = 13 π (400-3x2). Let V ′ = 0, then the solution is X1 = 2033, X2 = - 2033 (rounding off). When 0 ＜ x ＜ 2033, V ′＞ 0; when 2033 ＜ x ＜ 20, V ′＜ 0; when x = 2033, V takes the maximum value
RELATED INFORMATIONS
- 1. To make a conical funnel, its generatrix length is 20 cm, and its height should be () cm A. 2033B. 100C. 20D. 203
- 2. The volume of an approximate conical funnel is 132 cubic centimeters, the bottom area is 44 square centimeters, and the height of the funnel is () cm
- 3. A conical funnel with a volume of 120 square centimeters is measured to be 10 centimeters high. The bottom area of the funnel is calculated
- 4. Conical surface area formula
- 5. The diameter of conical chimneys is 80cm, and the length of bus is 50cm. To make 100 such chimneys, it is necessary at least______ M2 of iron sheet (the result retains π)
- 6. How many cm long wooden strips do you need to make a cuboid frame? The length is 35cm, the width is 20cm, and the height is 20cm
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- 8. The radius of sector AOB is 12cm, and the angle AOB is 120 degrees. The length of arc AB (the result is accurate to 0.1cm) and the area of sector AOB (the result is accurate to 0.1 square centimeter) are calculated
- 9. If you want to make a cone-shaped object, how can you find the fan-shaped object after the cone is expanded?
- 10. If the height of a cuboid box is reduced by 5cm, it becomes a cuboid box. At this time, the surface area is reduced by 120cm, How many square centimeters of cardboard are used in the original box?
- 11. There is a conical funnel with a volume of 314 cubic centimeters. Its height is 10 centimeters. What is its bottom area?
- 12. About fluid, why use inverted funnel when blowing table tennis
- 13. Why use a funnel to blow a table tennis ball,
- 14. What's the phenomenon that a ping-pong ball won't fall when a funnel blows
- 15. How much is the surface area of a cuboid 20 cm long, 15 cm wide and 5 cm high divided into two parts along the height of the block?
- 16. A cuboid glass jar is 15 cm long, 12 cm wide and 10 cm high. The water depth inside is 8.5 cm, and then a cube block with 8 cm edge length is put into the water
- 17. The cuboid container with water is 20cm in length, 15cm in width and 10cm in height. After a tomato is put in, the water surface rises 5cm. What is the volume of tomato? A cube with a surface area of 10m and a volume of 100m and 179 The edge length of the box is 6.4 decimeters, the thickness of the board is 0.2 decimeters, and the volume of the box is [] A. 262.144 cubic decimeter b.265.18 cubic decimeter The cuboid container with water is 20cm in length, 15cm in width and 10cm in height. When a tomato is put in, the water surface rises 5cm and the volume of tomato is () DM;.
- 18. It is known that the side lengths of two bottom surfaces of a regular triangular pyramid are 30cm and 20cm respectively, and the side area is equal to the sum of the two bottom areas
- 19. 1. A cylinder with a bottom diameter of 10 cm and a height of 15 cm is cut into two and a half cylinders along the diameter 1. A cylinder with a diameter of 10cm at the bottom and a height of 15cm is cut into two half cylinders along the diameter. How many square centimeters does the surface area of the two half cylinders increase compared with that of the original cylinder? 2. A cylindrical oil barrel, full of oil, poured out 3 / 4 of the oil in the barrel, and there are 20 liters left. The height of the oil barrel is 8 decimeters. How many square decimeters is the bottom area of the oil barrel? 3. A cylindrical tank contains 10 cm deep water, and the bottom area of the tank is 300 square cm? 4. After sawing a 2-meter-long log into equal segments for three times, the surface area increases by 48 square centimeters. What is the original volume of the log?
- 20. Cut a cone with a base radius of 5cm into two parts vertically from the top along the height. At this time, the surface area will be increased by 180cm2, and the volume will be calculated