To analyze the scenario, we can use the wave relationship described by the equation:
\[ v = f \lambda \]
where:
- \( v \) is the speed of the wave,
- \( f \) is the frequency,
- \( \lambda \) is the wavelength.
When the wave travels from one medium to another, its frequency remains constant because it is determined by the source of the wave.
Given that the wavelength triples in the new medium (let's denote the original wavelength as \( \lambda_1 \) and the new wavelength as \( \lambda_2 = 3\lambda_1 \)):
- When the wavelength increases (triples in this case), the speed of the wave must also increase in order for the relationship \( v = f \lambda \) to hold true, since the frequency (\( f \)) remains unchanged.
Thus, if the wavelength triples, the speed in the new medium will also triple.
Therefore, the correct answer is:
The speed will triple, and the frequency will stay the same.