Final answer:
Ultrasonic testing (B) is the method using sound waves to identify defects in aerial apparatus components. While the formula for calculating ultrasonic wave travel time can be used, the speed of sound in the material is necessary for finding the exact time required for the waves to travel through the frying pan coating of 1.00 mm thickness.
Step-by-step explanation:
The aerial apparatus test conducted by using sound waves and a scope to identify defects in the bolts, ladder pins, sheave wheel pins, and ladder base rails of an aerial apparatus is known as Ultrasonic testing (B). This non-destructive testing method employs high-frequency sound waves that are transmitted throughout the object being inspected. Changes in the sound waves' behavior, due to their interaction with internal flaws or irregularities, can be observed and analyzed. For example, NASA developed an ultrasonic bolt elongation monitor that tests tension and high-pressure loads on bolts and fasteners, which has evolved into various applications, including non-destructive evaluation.
The time recorded for ultrasonic waves to travel through a nonstick-coated frying pan's coating and return should correspond to the required coating thickness of 1.00 mm. Given the frequency of the sound waves as ƒ = 25 kHz and their wavelength in the coating as 0.076 m, the correct travel time can be calculated using the formula for wave speed (velocity = frequency × wavelength) in conjunction with the thickness of the coating. However, to compute the time, we would need the speed of sound in the coating material, which is not provided.