Velocity proportional to wavelength?

1. Jun 4, 2008

v_pino

There are two equations I know of that link velocity and wavelength:

1 velocity = frequency x wavelength

2 de broglie wavelength= planck's constant/ (mass x velocity)

I read that 'When particles are accelerated to high velocities, they have low wavelengths'.
This means that velocity has to be inversely proportional to wavelength, and this would come from the second equation. But why?

Thanks :)

2. Jun 4, 2008

pam

The velocity in v=f*lambda is the wave velocity of a wave.
The velocity in 2 is the velocity of particle in de Broglie's conjecture for the wavelength of the wave function associated with the particle's motion.

3. Jun 4, 2008

lightarrow

In other words: they are not the same velocity, but two different ones; the first is also called "phase" velocity, the second "group" velocity.