Wave a is being decreased in temperature, and wave b is moving from a liquid to a gas medium.

which statement can be made about both waves?

they will speed up.
they will increase the density of their medium.
they will slow down.
they will decrease the density of their medium.

The correct answer is they will slow down.

Explanation:

Speed of the wave depends on the temperature of the system. Higher the temperature, the particle will vibrate more and hence, the speed of the wave will be high.

As, the temperature is decreased, the wave will slow down.

We are assuming that the Wave B is longitudinal wave and it travels the fastest in solids because, these waves require a medium to travel and in solid, the particles are closely packed and the vibrations will travel easily, then in liquids and then in gaseous state.

Thus, while moving from liquid to gas medium, the wave B will slow down.

Hence, the correct answer is they will slow down.

e/c, where e is its total energy