Explanations:

The de Broglie wavelength is given by the equation:

λ = h/p

where λ is the wavelength, h is Planck's constant, and p is the momentum.

Momentum is defined as the mass times the velocity.

So, the de Broglie wavelength is inversely proportional to the velocity of the particle.

Therefore, as the velocity increases, the de Broglie wavelength decreases or gets shorter.