Final answer:
A certified mechanic with a powerplant rating can carry out a range of propeller repairs, excluding complex procedures needing specialized equipment.
Step-by-step explanation:
The propeller repairs can be performed by a certified mechanic with a powerplant rating. A certified mechanic with a powerplant rating is qualified to carry out maintenance and certain repair tasks on aircraft engines and their components, including propellers. These repairs can range from minor surface damage rectification to more significant repairs as long as they do not involve complex procedures that require specialized equipment or fabrication of parts, which might necessitate additional certifications or an appropriately rated repair station.
Regarding the specific example given in the question where the propeller's angular velocity decreases at a constant rate after the engine is shut off, the calculation would involve basic kinematic equations to determine the rotation rate after a certain time has elapsed. If a propeller's angular velocity is decreased at a constant deceleration of 2.0 rad/s² for 40 seconds, you can use the equation ω = ω0 - αt, where ω is the final angular velocity, ω0 is the initial angular velocity (converted from revolutions per second to radians per second), α is the angular deceleration, and t is time. However, assessing if the situation is reasonable requires interpreting the physical context of the propeller's function and typical performance characteristics.