Oscillations in many devices such as musical instruments are desirable. However, many oscillations. such as those caused by winds or eaithquakes, can be very destructive. {aJDene what is meant by resonant frequency, forced frequency. and mechanical resonance. Give an example of each. (3 marks] [hJGive an example of a stmcture or machine in which mechanical resonance may be used to advantage. Describe how mechanical resonance is used in this device. (1 mark} (clive an example or situation in which oscillations are undesirable. Describe what scientists and engineers can do to eliminate or reduce the effects of unwanted osciilalions. (1 mark}