Reflection of Waves
The bouncing hack of waveform the boundary of a medium is calleded reflection of the wave.
When a wave produced in one medium ‘travel to the boundary to enter into another medium, then a part of the incident wave is reflected from the boundary. This reflectc$part has the same frequency and wavelength as the incident wave has. But there may be a change. Of phase which depends uporu the nature of boundary of the medium.
Reflection of waves from the boundary of the denser medium:
Let us take a long slinky spring whose one end is fixed to rigid support on a horizontal surface of a table, The other end of this spring is free to oscillate. A sharp jerk is given to which a crest or through is produced on it. It travels on the spring from its end A towards the end d. On reaching at end B spring exerts a force On the rigid support to produce similar motion in it. But the rigid body has high-density sc it exertS equal and opposite reaction on the spring. Due to which crest is converted into ‘rough and it travels back from end B to A.
Reflection Of Waves from the boundary of a rare medium
If We attach end B of long slinky spring With a light string and keep its end A free, like before, Then giving a sudden jerk to end A, a crest is produced which travels on the spring from its end A to end B. When the crest produced reaches the ‘boundary of string. Then string being tare medium, do not give reaction to the spring. So that a crest is reflected as a crest on the spring from end to end Its: If a transverse wave traveling in a rarer medium is incident on a denser medium, it is reflected such that •it undergoes a phase change Of 1809.