A source produces 15 crests and 15 troughs in 3 seconds. When the second crest is produced, the first is 2 cm away from the source. Calculate:
(a) Frequency
(b) Wavelength
(c) Speed of wave

a) (a) 5 Hz, (b) 0.4 cm, (c) 1.2 cm/s
b) (a) 3 Hz, (b) 0.2 cm, (c) 0.6 cm/s
c) (a) 10 Hz, (b) 0.8 cm, (c) 2.4 cm/s
d) (a) 2 Hz, (b) 0.1 cm, (c) 0.3 cm/s