Final answer:
The amplitude of a wave is half the distance from the crest to the trough. If this distance is 0.6 meters, then the amplitude is 0.3 meters.
Step-by-step explanation:
If the distance between the crest and trough of a wave is 0.6 meters, we know that this distance covers from the highest point of the wave (the crest) to the lowest point of the wave (the trough). The amplitude of a wave is defined as the height from the rest position (the still water surface level if talking about water waves) to a crest. Since the distance from the crest to the trough is twice the amplitude (crest to rest position and then rest position to trough), the amplitude is half of 0.6 meters, which would be 0.3 meters. Therefore, the correct answer is a) 0.3 m.
The amplitude of a wave does not equal the distance between the crest and the trough, nor is it the same as the total wave height, which is the distance between the trough and the crest. Instead, it's specifically the vertical distance from the rest position to the crest or to the trough, and thus is half the peak-to-trough height.