What is called the phenomenon of prolongation of sound​

It is called reverberation.

Explanation:

The phenomenon of prolongation of sound is the process in which sound produced is reflected from plane surfaces in a continuous manner, which leads to reverberation of sound waves. It can also be referred to as a condition of continuous echo production.

It occurs when sound produced get reflected from a hard plane surface, and in the process hits another surface and another reflection occurs. This continuous reflection leads to prolongation of sound.

The sound produced is heard for some specific period of time before it dies down or get absorbed finally.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

the amount of current in the coil