In a lab investigating the concept of energy transfer through resonance, these instructions were followed: At this lab station, you'll observe the effect of sympathetic resonance that occurs when two objects with the same natural frequency come into close proximity. Make sure that the hanging ball is just barely touching one of the resonance boxes. Make sure that the openings of the boxes are close together. Use the mallet to strike the tuning fork on top of the resonance box without the hanging ball. If done correctly, the hanging ball should begin to bounce. How is the bouncing of the ball proof that energy was transfered by the sound waves