A student projects a wave pattern from a ripple tank onto a viewing screen below.
The projected waves span across a screen that is 120 cm long.
What is the wavelength of these waves as shown on the screen?
12 cm12\text{ cm}12 cm
20 cm20\text{ cm}20 cm
60 cm60\text{ cm}60 cm
120 cm120\text{ cm}120 cm