Waves II. I need help figuring out the harmonics.

1. The problem statement, all variables and given/known data
A steel rod of length 1.44 m is clamped at a point 1/4 of its length from one end. The ends of the rod are free to vibrate. If the velocity of longitudianl wave in steel is 5000 m/s, find the frequency of the first three allowed harmonics. Make diagrams to show the three standing waves.

2. Relevant equations
f = (nV) / 2L

because it has two open ends. Their not actually open but they both are free which means the same thing.

3. The attempt at a solution

I have the answers. I'm just clueless as to how you figure out n for each harmonic.

Shouldn't it just be 1, 2 and 3.

For some reason my classmates gor 2, 6 and 10.

And all you have to do is plug it in to find each of the three frequencies.

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