Why might strobe frequencies lower than the frequency of vibration of the rope appear to "freeze" it?

Question

Why might strobe frequencies lower than the frequency of vibration of the rope appear to "freeze" it? What frequencies would do this?

Answer 1

vibration frequencies evenly divisable by the strobe frequency

Answer 2

Only strobe frequencies that are an exact sub-multiple of the vibration frequency will "freeze" the rope. For a "freeze" to occur, the strobe must flash only when the rope is in the same position every time. For example, if the strobe occurs only when the rope is at its maximum excursion upward, you only see the rope in that position and not in its other positions. Therefore it appears stationary. It does not have to be lit every time in that position, so the frequency of the strobe can be some integer division of the rope frequency.

Answer 3

Strobe frequencies that divide evenly into the vibration frequency will do this. This is because a whole number of waves have passed. For instance, if the rope is vibrating at 10 Hz and you strobe it at 5Hz, exactly two waves will pass between each strobe, so the rope will be in the same position as at the previous strobe.

Answer 4

The question is defective: Frequency, the inverse of wavelength, has no longer something to do with the quantity of skill of a sound wave. A wave is defined in area via 3 residences: Frequency, Amplitude, and section Shift. each and every is autonomous of one yet another. So, Amplitude could properly be something (huge or tiny) for any frequency. often even with the undeniable fact that, larger frequency waves attenuate speedier than low frequency waves (except in a vacuum), so all issues being equivalent in case you have a applicable resource, producing waves of all frequencies with the best comparable amplitude and additionally you're measuring the amplitude of each and every frequency at a protracted way from the resource, the measured amplitude of the decrease frequency waves would be larger than that of the intense frequency waves. it is clarification why you are able to purely truly pay attention the backside noise from autos that have their audio device cranked up loud whilst they are close by.