Resonant interaction

Have you ever tried pushing someone on a swing at just the right moment? If you time it perfectly, the swing can go super high! That's a bit like resonant interaction.

Resonance happens when two things are vibrating at the same speed or frequency, like the swing moving back and forth. When you push at just the right time, you add more energy to the swing and make it go even higher! This is called a resonant interaction.

The same thing can happen with other things that vibrate, like sound waves. If you sing a note and hold a glass up to your mouth, you might notice that the glass starts to vibrate too. If you keep singing, the glass might even break! This is because the sound waves and vibrations from your voice are resonating with the glass, causing it to vibrate more and more until it can't handle it anymore.

So, resonant interaction is when two things are vibrating at the same frequency and one object adds more energy to the other. Just like pushing someone on a swing at the perfect moment can make them go higher than ever before!