Question

If during the verification of the law of reflection of sound, the angle between the incident sound wave and reflected sound wave is $90^\circ $. What is the angle of incidence? What kind of wave can be produced by slinky?

Answer 1

Hint: The sound wave is a longitudinal wave which means that the particles of medium due to sound propagates parallel to the direction of motion. The sound wave needs medium to propagate from one point to another point.

Complete step by step solution:
It is asked in the problem that if during the verification of the law of reflection of sound, the angle between the incident sound wave and reflected sound wave is $90^\circ $then we need to find the angle of incidence and also the kind of wave can be produced by slinky.
If the angle between the incidence and reflected angle is $90^\circ $ then the normal passes through half of the angle and therefore the angle of incidence is equal to $45^\circ $ which is half of the angle between the incidence and reflected sound wave.

The slinky is a set of coils and when a coil of slinky is stretched horizontally and released then the vibration produced is parallel to the direction of the end point of slinky. As the vibration is parallel to the direction of the end point of the slinky and therefore the wave produced by the slinky is a longitudinal wave.

Note: The students should understand and remember that the waves can be of two types one is known as longitudinal and other is transverse wave. The transverse wave is produced when the vibration is produced perpendicular to the direction of motion of the wave and the longitudinal wave is produced when the vibration is produced parallel to the direction of motion of the wave.