Which description fits the thrust curve of a progressive motor?

The description that best fits the thrust curve of a progressive motor is one that indicates a general increase in thrust during the burn. Progressive motors are designed to produce an increasing amount of thrust over the course of their burn time, which provides a smooth acceleration to the rocket. This characteristic helps in achieving better performance and stability during the flight, as the rocket gains speed gradually.

This type of thrust curve is particularly beneficial in reducing structural stresses on the rocket and improving its overall flight dynamics. The gradual buildup of thrust helps minimize the chances of exceeding the rocket's structural limits by avoiding sudden spikes in force. Understanding this behavior is crucial for rocketry design and flight planning, as it directly influences the ascent profile and stability of the rocket during its launch phase.