You need to provide more context to determine the correct unit for a wavespeed of 1.5. "Wavespeed" refers to the speed at which a wave travels, and the unit depends on what type of wave we're talking about. Here are some possibilities:

* Meters per second (m/s): This is the standard unit for speed, and it's commonly used for waves in various media, like sound waves in air or water waves.

* Kilometers per hour (km/h): This unit is often used for waves traveling long distances, like ocean waves.

* Centimeters per second (cm/s): This unit might be used for smaller waves or in situations where a more precise measurement is needed.

To determine the correct unit, tell me:

* What type of wave is it? (e.g., sound, light, water, etc.)

* What is the medium the wave is traveling through? (e.g., air, water, a string, etc.)

Once you provide this information, I can help you determine the appropriate unit for a wavespeed of 1.5.