Group Velocity

[yellowgold]

What is the relationship wavelength and group velocity in wave packet ? If a wave packet has big wavelength its group velocity bigger or not ?

[malawi_glenn]

What is the relationship wavelength and group velocity in wave packet ? If a wave packet has big wavelength its group velocity bigger or not ?

If you know the definition of group velocity you can do this by yourself as an exercise. Recall the relation between (de Broigle) wavelenght v.s momentum and then you have it.