In a ripple tank experiment to demonstrate interference, two point sources having a common frequency of/6.0 HZ are used. The sources are 5.0 cm apart and are in phase. A
metre stick is placed above the water, parallel to the line joining the two sources. The first
nodal lines (one on either side of the central axis) cross the metre stick at the 35 cm and
55 cm marks. Each of the crossing points is 50 cm from the midpoint of the line joining
the two sources. Calculate the wavelength and speed of the waves.