When two sets of progressive wave trains of the same type, having same amplitude an same time period, travelling with same speed along the same straight line in opposite directions superimpose, a new set of waves are formed. These are called stationary waves or standing waves. The resultant waves do not propagate in any direction, nor there is any transfer of energy in the medium.
Read the above passage and answer the following questions:
(i) Stationary waves are characterised by nodes and antinodes. What are these points ?
(ii) What is the total energy associated with a stationary wave ? What values of life do you learn from this ?

Explanation

(i) Nodes are the points in a medium in a stationary wave, which are permanantly at rest. Antinodes are the points in a medium in a stationary wave, the amplitude of vibration of which is maximum.
(ii) The total energy associated with a stationary wave is twice the energy of each of incident and reflected wave. And there is no flow or transference of energy along the stationary wave.
In stationary waves, disturbance is confined to a particular region. It does not travel on and on. In day to day life, it implies that when you confine your activities to a particular domain, all your energy is utilized in that domain and you become a great achiever. The idea points towards specialization in a particular field and becoming master of it, rather than diversifying and becoming jack of all trades, master of none.