The frequency of a string is inversely proportional to its length, so we can write the following relation:
[tex]f\cdot L=k[/tex]For f = 480 Hz and L = 1 m, we have:
[tex]k=480\cdot1=480[/tex]Now, let's find the frequency for the following lengths:
A. 33.3 cm:
[tex]\begin{gathered} f\cdot0.333=480 \\ f=1440\text{ Hz} \end{gathered}[/tex]B. 25 cm:
[tex]\begin{gathered} f\cdot0.25=480 \\ f=1920\text{ Hz} \end{gathered}[/tex]C. 50 cm:
[tex]\begin{gathered} f\cdot0.5=480 \\ f=960\text{ Hz} \end{gathered}[/tex]D. 10 cm:
[tex]\begin{gathered} f\cdot0.1=480 \\ f=4800\text{ Hz} \end{gathered}[/tex]