Within a single medium, the product of (wavelength) x (frequency) is always the same number, for all waves. (It's the wave-speed.)
This means that longer wavelengths must have lower frequencies, and shorter wavelengths must have higher frequencies, in order for the product to always come out to be the same.
Since like poles repel, the two horseshoe magnets have like poles facing each other, hence they repel each other and therefore they will not come in contact
