Question

A student investigates the speed of sound and light through four new substances.



The data table shows the densities of each substance.



Substance
Density

(g/cm3)

A 0.364
B 1.40
C 0.79
D 1.26




Which statement BEST compares the speed of light and sound through the substances?




Light will travel faster in Substance D than in Substance A.


Light will travel faster in Substance C than in Substance D.


Sound will travel faster in Substance C than in Substance B.


Sound will travel faster in Substance A than in Substance B.



Part B:



Which statement BEST supports the choice in Part A?


The particles in Substance A are farther apart than in Substance B.


The particles in Substance A are farther apart than in Substance D.


The particles in Substance C are farther apart than in Substance B.


The particles in Substance C are farther apart than in Substance D.

Answer 1

Part A: Light will travel faster in Substance C than in Substance D.

Reason: C has lower density (0.79 g/cm3) than D (1.26 g/cm3), and light travels faster in less optically dense media.

Part B: The particles in Substance C are farther apart than in Substance D.

This explains the lower density of C vs D, which supports why light travels faster in C.