A suspension system is being designed for a 1300 kg vehicle. When the vehicle is empty, its static deflection is measured as 2.5

All the weight of the wooden board rests solely on the support situated at the center of the rod, while the other support positioned at one end experiences no reaction force, resulting in a 0 reaction force.

Thus, the reaction force at the central support corresponds to the weight of the board, whereas the end support has 0 reaction force.

The correct term is accretion disk. This refers to a formation, typically a circumstellar disk, created by dispersed matter revolving around a large central body, which is usually a star. The gravitational pull causes the material in the disk to spiral inward towards the center.