a. A standing wave with wavelength λ is formed in a free rod of length L, on the end of which a harmonic force acts with frequency ω. Where are the stress nodes of this wave? What is the amplitude of the forcing force if the amplitude of the stress in the standing wave is σ0 and the cross section of the rod is S.
b. Construct a resonance curve - a graph of the dependence of the value F0σ0S on the frequency of the forcing force. Determine the frequencies at which F0σ0S will increase indefinitely. Is it possible to state that these frequencies coincide with the natural frequencies of oscillations of the rod when no external forces act on it?