In my book, an experiment to demonstrate resonance if given with the help of tuning force.
The book suggests the use of two identical tuning forks on two separate sound boxes such that their open end face each other.
The reason given for the use of sound boxes is to produce vibrations of large amplitude because of large surface area of air in the sound box.
My question is since amplitude is basically the energy possessed by the wave, shouldn't it be constant and decrease instead of increasing in the sound box. The tuning fork produces some 'x' amplitude. Now when the air molecules are hit, shouldn't they receive less amplitude as the vibrations from the fork are transferred to the air box's surface and then air.
It would be great if someone could explain why the vibrations in the air box are of larger amplitude than the air surrounding the tuning fork.
(P.s I am a high school student and would prefer explanations in layman's language. Thanks)