The driving and driven members are rotating in the same direction.

A member (1) moves towards and tries to cross the another member (2) at certain speed

Member (1)'s speed of attack and acting load on the member (2) will decrease due to the movement of member (2).

The RPM of all gears in the gearbox is directly proportional to the acceleration as per the gear ratios. So due to the acceleration, the RPM of all gears will change according to the gear ratios.

Gear ratios are inversely proportional to the speed of the vehicle during gear shifts.

All blocks in the driving and driven members will resist with each other at the same time.