Final answer:
Dynamic brakes aid in stopping a train by activating the electric motors to generate braking force, a process that converts the train's kinetic energy into electrical energy.
Step-by-step explanation:
Dynamic brakes on trains contribute to the stopping process by activating the electric motors to generate braking force. This system works by converting the kinetic energy of the train into electrical energy, which can then be dissipated as heat through resistors or, in the case of regenerative braking systems, can be fed back into the power supply system. Unlike traditional air brakes that use pressurized air to apply mechanical force to brake shoes and slow down the train, dynamic brakes utilize the train's electric motors as generators when slowing down, thereby creating a braking force.
George Westinghouse's invention of the pneumatic air brake was a significant advancement in train technology as it allowed for safer and faster train travel by enabling the engineer to apply brakes from the locomotive. Conversely, dynamic brakes represent another leap in technology, harnessing the principles of physics to improve efficiency and safety in modern train systems.