Final answer:
Air brakes in heavy trucks use compressed air to transfer braking force, whereas hydraulic brakes use liquids based on Pascal's principle. Overheating of brakes happens when potential energy is converted to heat energy too quickly, which can lead to brake failure. Proper maintenance like bleeding air from the lines is essential for brake efficiency, as shown in various figures discussing braking systems and their physical principles.
Step-by-step explanation:
The question asked pertains to the functionality of air brakes in vehicles, particularly in heavy trucks. Air brakes rely on compressed air to transmit pressure from the control mechanism to the braking mechanism. These systems can be compared with hydraulic brakes, which use fluids to achieve the same end: to transfer force from the driver's pedal action to the brake pads or shoes which slow down the vehicle by using Pascal's principle.
The mechanical equivalent of heat is observed when brakes overheat, as evidenced by smoke from the brakes of a truck. When brakes are applied especially during a downhill run, gravitational potential energy is transformed into increased internal energy (heat) of the brake material, which is necessary to prevent the conversion of this potential energy into kinetic energy of the truck, potentially avoiding an uncontrolled descent. However, if the heating occurs too rapidly, the brakes can fail since the mass of the truck is very large compared to that of the brake material, and adequate heat transfer to the environment can't occur quickly enough.
The inclusion of Figure 14.5, Figure 11.17, and Figure 14.18 points to the applied physics and mechanical principles involved in the functioning and design of braking systems in vehicles, and why maintaining the efficiency of these systems, such as bleeding air from brake lines, is crucial for safe and effective operation.