waves are the kind of disturbance as its definition will clear you.waves are produced by disturbance in source in static position. In rivers and lakes water is already in dynamic position so no effect of disturbance.
when water is in static means still water or water that is in no motion or in motion in only one direction .i have used static for this and dynamic i used for motion in random directions.
Rightly said by Gulshankumarji, tides are the reasons we have waves in seas and not in rivers. Also tides give rise to the sea getting close to land or going far away.
thank you isha. But i have another doubt that is moon will be at night time so it can attract the sea at night time but we can see tides at morning also. what is the reason behind this
