A mechanical oscillator fixed at one end of a stretched, lightweight cord produces continuous transverse waves of frequency 45Hz. After traveling 2.4m along this cord (medium 1), the waves reach a junction with a heavier cord (medium 2). Wave speeds are 18ms−1 in medium 1 and 12ms−1 in medium 2.
(a) Determine the wavelength of the waves in medium 1 and the wavelength of the transmitted waves in medium 2.
(b) State whether the pulse reflected at the junction is inverted. Justify your answer using properties of the two media.
(c) Calculate the time required for a crest produced by the oscillator to travel from the oscillator to the junction.
(d) During the interval calculated in part (c), how many complete oscillations does the source execute? Explain how your answer is consistent with the behaviour of the transmitted and reflected waves.