Question

a student is performing an experiment comparing sound and light waves. the student gathers the following data.

speed of sound

medium	temperature (°c)	speed of sound (m/s)
water	25	1500 m/s
steam	100	346 m/s

speed of light

medium	index of refraction	speed of light (m/s)
water	1.33	2.26×10⁸
glass	1.57	1.91×10⁸

what conclusion does the student most likely make based on this data?
○ light waves always travel the same speed; however, the speed of sound is determined by the medium that it travels through.
○ all sound waves always have the same energy, so the temperature of the medium does not affect wave speed.
○ light needs to vibrate particles, so it travels fastest in tightly packed solids, while sound does not need a medium, so it travels fastest in a gas.
○ tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.

Explanation:

Light is an electromagnetic wave that doesn't require a medium to travel. Its speed in a medium depends on the medium's optical density (index of refraction). Solids (like glass) have a higher index of refraction than gases (like air), so light slows down in solids. Sound is a mechanical wave that travels by particle - to - particle interaction. In solids (like ice), particles are closely packed. When a sound wave passes, particles can quickly transfer the energy (by bouncing into each other), resulting in a higher speed of sound compared to gases (like steam) where particles are more spread out.

Answer:

Tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.