A student is transmitting sound waves through various materials. Through which metal in the table will the sound waves travel the fastest?

\begin{tabular}{|c|c|c|c|c|}
\hline & Aluminum & \begin{tabular}{c}
Brass \\
[tex]$(70 \% Cu$[/tex], \\
[tex]$30 \% Zn )$[/tex]
\end{tabular} & Copper & Lead \\
\hline \begin{tabular}{c}
Speed of \\
sound \\
[tex]$( m / s )$[/tex]
\end{tabular} & 6,420 & 4,700 & 5,010 & 1,960 \\
\hline
\end{tabular}

A. Brass
B. Copper
C. Lead
D. Aluminum



Answer :

To determine through which metal the sound waves will travel the fastest, we need to compare the speeds of sound in the given materials. According to the table, the speeds of sound in the various metals are provided.

1. Aluminum: 6,420 m/s
2. Brass (70% Cu, 30% Zn): 4,700 m/s
3. Copper: 5,010 m/s
4. Lead: 1,960 m/s

We need to identify the metal with the highest speed of sound.

- The speed of sound in Aluminum is 6,420 m/s.
- The speed of sound in Brass is 4,700 m/s.
- The speed of sound in Copper is 5,010 m/s.
- The speed of sound in Lead is 1,960 m/s.

Comparing these speeds, we notice that:

- 6,420 m/s (Aluminum) is greater than 4,700 m/s (Brass).
- 6,420 m/s (Aluminum) is greater than 5,010 m/s (Copper).
- 6,420 m/s (Aluminum) is greater than 1,960 m/s (Lead).

Therefore, the highest speed of sound is 6,420 m/s, which corresponds to Aluminum.

Thus, the sound waves travel the fastest through Aluminum.

The correct answer is:
D. Aluminum