But here if 10 waves starts from one point, they will immediately space out. A ship is creating lot of waves here. Right now, you met lot of waves you ten stones, but eventually if suppose it met number of waves, suppose you took like various kind of poking and making waves, soon they will separate all. Because the one that you are making at a high frequency wave would have travelled in some time only this much, the other longer one would have travelled more. So, they would have dispersed out. This is why it is called waves are dispersive. Longer wave would have travelled faster. So, if there is a volcanic eruption, it makes all kind of waves, but the longest one will reach your coast fast, shorter one will take long time to come. So, this is very important. See, this part that longer waves travel faster, shorter waves travels slower. In fact, we will find out from this relation what can be the typical speed of a wave. You see you take this part, C equal to root over of g lambda by 2 pi.