A wave is a disturbance that travels through a medium (like a rope, air, or water) carrying energy from one place to another without transporting matter. Think of it as a ripple that moves across a pond after you drop a stone. The shape of the disturbance repeats itself as it moves.
When you hold one end of a rope and shake the other, you create a transverse wave. The rope moves up and down while the wave travels along the rope.
A spring can support both transverse and longitudinal waves. When you compress or stretch a spring and release it, the disturbance travels along the spring.
A ripple tank is a shallow dish of water that lets us see waves in two dimensions. By dropping a stone or using a vibrating plate, you can observe circular or standing waves.
Key observations:
| Parameter | Symbol | Typical Value (example) |
|---|---|---|
| Amplitude | \$A\$ | 0.5 m (rope) |
| Wavelength | \$\lambda\$ | 2 m (rope) |
| Frequency | \$f\$ | 1 Hz (rope) |
| Speed | \$v\$ | 2 m s⁻¹ (rope) |
Imagine a line of people holding hands. If the first person jumps up, the motion travels down the line like a wave. Each person moves up and down, but the overall pattern (the wave) moves forward. This is exactly what happens in ropes, springs, and ripple tanks – the disturbance moves, but the individual particles (or water molecules) return to their original positions after the wave passes.
Progressive waves transport energy through a medium by transferring motion from one particle to the next. Whether it’s a rope, a spring, or water in a ripple tank, the same fundamental principles—amplitude, wavelength, frequency, and speed—describe how the wave behaves.