Final answer:
An automatic speed regulator such as cruise control maintains a vehicle's speed by making automatic throttle adjustments, whereas air speed indicators in aircraft achieve a similar outcome for maintaining constant speed. Devices like speedometers display instantaneous speed but do not control it.
Step-by-step explanation:
Automatic Speed Regulators
A device that can act as an automatic speed regulator is cruise control. This system is typically found in automobiles and is designed to maintain a vehicle's speed at a set level. When engaged, cruise control monitors the car's speed, making automatic throttle adjustments to ensure the vehicle remains within a certain speed range. If the vehicle begins to exceed the set speed, cruise control reduces the gas flow, slowing the car down. Conversely, if the speed falls below the desired level, it increases the gas flow to accelerate.
Another example of a speed regulator is found in aviation. Air speed indicators in aircraft measure fluid velocities and help pilots maintain constant speed. These devices are crucial for safety and efficiency in air travel.
It's also worth noting that vehicles have devices such as a speedometer to indicate instantaneous speed. However, unlike cruise control and air speed indicators, the speedometer only displays current speed and does not control it.
In a physics context, understanding how these systems work involves concepts like force, velocity, resistance, and control mechanisms. The cruise control system in cars, for instance, works on the principle that the required force to maintain a certain speed is directly proportional to that speed.