Super difficult exercises of solving cylinder and cone More is better! Thank you very much!

Super difficult exercises of solving cylinder and cone More is better! Thank you very much!


The volume of a cone is 45 cubic centimeters. If its bottom radius is reduced to one third of the original and its height is expanded to two times of the original, what is its volume?
The volume of a cylinder and a cone is equal. The ratio of the height of the cylinder to the height of the cone is 4:9. The bottom area of the cone is 20 square centimeters. How many square centimeters is the bottom area of the cylinder?
There is water in the cylindrical glass. The water surface is 5cm high and the bottom diameter is 8cm. After the cylinder with the bottom diameter of 4cm and height of 6cm is vertically placed in the glass, the water surface does not submerge the cylinder. How many cm is the water surface high?
There are two cylindrical containers a and B. at first, container a contains 2 liters of water, and container B is empty. Now, water is injected into the two containers at a flow rate of 0.4 liters per minute. After 4 minutes, the water surface heights of the two containers are equal. Suppose the bottom radius of B is 5 cm, then what is the bottom diameter of a?



A cylinder with a radius of 4cm at the bottom and a height of 9cm is cut into the largest cone. What is the volume of the cone in cubic centimeter? What is the volume of the cut part? (π = 3)


The volume of the cylinder is: 3 × 42 × 9, = 3 × 16 × 9, = 432 (cubic centimeter); the volume of the cone is: 432 × 13 = 144 (cubic centimeter); the volume of the cut part is 432 × 23 = 288 (cubic centimeter); a: the volume of the cone is 144 cubic centimeter, and the volume of the cut part is 288 cubic centimeter



Proof of volume ratio of cone in Senior High School
Proof: the ratio of the volume of the small cone to the volume of the original cone obtained by cutting the cone parallel to the bottom plane of the cone is equal to the cube of the ratio of the height of the small cone to the height of the original cone


Because they are parallel sections, the proportions of radius and height are equal. Just list the expressions of two volumes and compare them
The calculation will come out soon