Current location - Training Enrollment Network - Mathematics courses - Who can tell me two math problems?
Who can tell me two math problems?
1, rotating with the width as the axis, that is, with the length as the bottom radius, its volume is:

3. 14× 12? ×5=2260.8(cm? )

2, cutting into a cylinder, there are three cutting methods:

1) With the surface composed of length and width as the bottom surface, the maximum diameter is 2.5dm, the height is 3dm, and the volume is (2.5/2)? π×3=4.6875π;

2) With the surface composed of width and height as the bottom surface, the maximum diameter is 2.5dm, the height is 3dm, and the volume is (2.5/2)? π×3=6.25π

3) The surface consisting of length and height is the bottom surface, with the maximum diameter of 3dm, the height of 2.5dm and the volume of (3/2)? π×2.5=5.625π

In the second case, the volume is the largest, and the volume of the cylinder is 6.25 π = 19.625 cubic decimeter.