What factors influence wave speed?

The speed of a wave is primarily influenced by the properties of the medium through which it travels, specifically medium density and elasticity. In a given medium, wave speed can be calculated using the relationship between these two factors.

When the density of a medium increases, assuming that the elasticity remains constant, the speed of the wave typically decreases because the particles in a denser medium can be more sluggish in transmitting the wave's energy. Conversely, if the elasticity of the medium increases, wave speed generally increases. This is because a more elastic medium allows for quicker restoration of the particle to its equilibrium position after being disturbed, resulting in faster wave propagation.

In contrast, factors such as wavelength, amplitude, or environmental temperature do not directly influence wave speed in a vacuum or a homogeneous medium. While they can affect other characteristics of the wave, such as energy and behavior, they do not change the fundamental speed at which the wave travels through a specific medium. Hence, the correct answer acknowledges the critical roles that medium density and elasticity play in determining wave speed.