Final answer:
In modern vehicle brake systems, the key principle is that fluids are incompressible. This allows for the effective transmission of brake pedal force to the wheel cylinders due to Pascal's Principle. Gases, which are compressible, are less efficient and must be bled from the system for proper brake function.
"the correct option is approximately option C"
Step-by-step explanation:
The key principle in a hydraulic system used in modern vehicle brake systems is based on the characteristic of fluids being incompressible. In such systems, when a force is applied to the brake pedal, it is magnified by a lever and then by the hydraulic system. Consequently, every wheel cylinder receives the same pressure and thus creates the same force output. This is an application of Pascal's Principle which states that pressure applied at any point upon an incompressible fluid within an enclosed system will be transmitted undiminished throughout the fluid in all directions.
Hydraulic systems leverage the incompressibility of liquids to efficiently transmit force through the system. These are critical for multiple applications in various mechanical systems, including automotive brakes and hydraulic jacks. Given that gases are compressible, they are not as effective in hydraulic systems because they can expand when pressure is applied. This is why air must be bled out of brake lines for brakes to function correctly.
A typical hydraulic system consists of two fluid-filled cylinders connected by a hydraulic line. When a force is applied to one piston, the resulting pressure is transmitted instantly and evenly to the second piston. Because liquids are nearly incompressible, this creates an efficient transfer of force, allowing for a larger force to be exerted where it is needed, as seen with the brake systems in vehicles.