posted by ashley -- .
Which of the following statements is not true about resonance?
Choose one answer.
a. It is easy to get an object to vibrate at its resonant frequencies but difficult to get it vibrate at other frequencies.
b. A simple pendulum has many resonant frequencies called harmonics.
c. A spring-mass system has only a single resonant frequency.
d. Vibrating strings and air-columns have many resonant frequencies called harmonics.