Explanation:
A governor is a device used in engines and machines to regulate the speed of the engine. It consists of a sleeve and a rotating shaft. The sleeve is connected to the throttle valve of the engine, and the rotating shaft is connected to a flywheel. As the speed of the engine increases, the flywheel rotates faster, causing the rotating shaft to move outward. This movement of the shaft causes the sleeve to slide up or down, adjusting the throttle valve and thus controlling the speed of the engine.

Constant Speed:
In the given scenario, the governor is running at a constant speed. This means that the flywheel and the rotating shaft are rotating at a constant rate, and there are no changes in the speed of the engine.

Force Acting on the Sleeve:
The force acting on the sleeve of the governor depends on the position of the rotating shaft. When the rotating shaft is at its maximum outward position, the force acting on the sleeve is zero. This is because at this position, the throttle valve is fully open, allowing maximum fuel flow to the engine, and there is no need for any force to be applied to the sleeve to adjust the throttle valve.

On the other hand, when the rotating shaft is at its minimum inward position, the force acting on the sleeve is also zero. This is because at this position, the throttle valve is fully closed, and again there is no need for any force to be applied to the sleeve to adjust the throttle valve.

Therefore, in both the maximum outward and minimum inward positions of the rotating shaft, the force acting on the sleeve is zero.

Conclusion:
In conclusion, for a governor running at constant speed, the force acting on the sleeve is zero. This is because there is no need for any adjustment of the throttle valve when the speed of the engine is constant.