HALF QUESTION Typical of Question 12 in Leaving Cert. Exam
Q3 Answer both of the following parts (a) and (b). (a) What is the Doppler Effect?
Explain, with the aid of labelled diagrams, how this phenomenon occurs. Describe an experiment to demonstrate this phenomenon.
(b) Dolphins emit high frequency waves when hunting for food.The wave reflects off, for example, a moving school of fish, and is detected by the dolphin.A dolphin emits a wave of frequency 12 kHz and wavelength 12.5 cm towards the school of fish. It detects the reflected wave 40 ms later. The frequency of the reflected wave is 12.1 kHz.
(i) Calculate the speed of the wave and the distance of the dolphin from the fish. (ii) Are the fish and the dolphin moving towards or away from each other? (iii) What is the speed of the fish relative to the dolphin?