Key ideas1 of 3
Choose suitable apparatus
A vibrator and dipper produce regular waves in a shallow ripple tank. A lamp makes the pattern easier to observe. Use a ruler at the water level, or a correctly calibrated image, to measure real wavelength. A projection can magnify distances: do not assume a screen distance is the same as the distance in the water. The vibrator’s measured or verified frequency, or video counting over a known time, gives frequency. Keep water depth steady.
