Based on the answers provided, the following corrections need to be made to the 3D object:

1. The second cylinder should be extruded from the bottom of the first cylinder. Currently, it is separate and serves as a base on which the first cylinder stands. 

2. The diameter of the second cylinder should be made clearly half of the first one. Currently, it is unclear if this is the case.

3. The length of the second cylinder should be increased to be five times that of the first one. Currently, it is significantly shorter than the first cylinder.