• You're chilling by a still lake.
• A boy skims a stone across the water.
• Splash! Ripples spread out, expanding like circles.
• The biggest disturbance? Where the stone first hit the water. The ripple gets larger as it moves further away from that point.

Real-world Example: Toss a pebble into a pond and watch the ripples flow! That first point of contact? That's where the wave begins.

• Wavefronts: Think of these like the frontline of an army, leading the charge! They move with the wave, always perpendicular (or at a 90° angle) to the direction the wave is heading. Each wavefront is one wavelength away from its neighbor.
• Rays: These are the arrows of energy, showing where the wave's energy is heading. They're like the straight lines that always stand perpendicular to our wavefronts.

Real-world Example: Imagine a fun day at a waterpark with circular floaties. Each floatie is a wavefront, and if you look at the direction everyone's sliding towards, those are the rays!

• Wavefronts tell a wave's story. The bigger its circle (or radius), the older the wave.
• Smaller circles = younger wavefronts.

Real-world Example: It's like reading tree rings. The more rings a tree has, the older it is!

• A transparent tank filled with just a tad bit of water.
• There’s a single light source that, when switched on, shines light through the water.
• Waves in the water make cool patterns of light and dark on a screen below. This is like a wave theatre!
  • Light areas = wave crests (high points)
  • Dark areas = wave troughs (low points)

Real-world Example: Picture a projector in a movie theatre. But instead of playing movies, it's showcasing water waves in action!