Final answer:
The wheel cylinder stops in a drum brake unit are designed to translate hydraulic pressure into mechanical force, applying the brake shoes against the drum to slow or stop a vehicle.
Step-by-step explanation:
The job of the wheel cylinder stops in a drum brake unit is to convert the hydraulic pressure from the master cylinder into mechanical force which then pushes the brake shoes against the drum, causing the vehicle to slow down or stop. This is based on Pascal's principle, which states that pressure applied at any point in a confined incompressible fluid is transmitted undiminished throughout the fluid. When a force of 100 N is applied to the brake pedal, it is increased by the lever system and the hydraulic system. Considering the hydraulic brakes system where each wheel cylinder has a diameter of 2.50 cm, the force exerted by each wheel cylinder can be calculated using Pascal's law and comparing the cross-sectional areas of the pedal cylinder (master cylinder) and the wheel cylinders (slave cylinders).