Question

Technician A says a fifth wheel release lever is located on the fifth wheel and may have a remotely released air cylinder that can be activated by the driver inside the cab. Technician B says an industry standard 2" (5.1 cm) kingpin has a minimum tow rating of 60,000 lb (27,215 kg). Who is correct

Answer 1

Technician A is correct regarding the fifth wheel release mechanism, while Technician B's statement falls outside the realm of hydraulics. To calculate the force needed in a hydraulic lift system to support a 2000-kg car, one must understand Pascal's law and the relationship between the pressures and areas in a hydraulic system.

Step-by-step explanation:

Technician A is correct that a fifth wheel release lever is located on the fifth wheel and may feature a remotely released air cylinder that can be activated by the driver inside the cab. This mechanism is an important part of the coupling and decoupling process for trailers. On the other hand, Technician B's statement about an industry standard 2" (5.1 cm) kingpin having a minimum tow rating of 60,000 lb (27,215 kg) is more related to the specifics of trucking industry standards rather than the physics of hydraulic systems.

The question about the force needed in a hydraulic lift system to support a 2000-kg car concerns the basic principles of hydraulics, particularly Pascal's law, which states that pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid and the walls of the containing vessel. The master cylinder's diameter allows us to calculate the area and thus the force needed by understanding that the hydraulic fluid will exert equal pressure across both the master and slave cylinders. Since the diameters of the master and slave cylinders are known, we can apply the formula for the area of a circle (πr²) to find the areas and then use the principles of hydraulics to find the force needed to support the car.

The significance of this calculation is that it shows how a hydraulic system can amplify force. A small force exerted on the master cylinder can result in a much larger force being exerted by the slave cylinder — this is due to the differences in the areas of the two cylinders. Understanding this principle is important in the design and operation of many types of machinery, including automotive lifts and backhoes.