# A Pendulum is vibrating freely in unforced oscillation

1. Aug 26, 2016

### andrespinilla

When the pendulum in Problem 3.8 is vibrating freely in unforced oscillation, the amplitude of its swing decreases by a factor of e after 75 cycles of oscillation. (a) Determine the Q-value of the pendulum. (b) The point of suspension of the pendulum is moved according to ξ = a cos ωt at the resonance frequency ωo with a = 0.5 mm. What will be the amplitude of swing of the pendulum? (c) Show that the width of the amplitude resonance curve at half height is equal to γ √3 and determine its value if the length of the pendulum is 1.5 m. (Assume g = 9.81 m s−2.) (Hint: Follow the approach of Section 3.3 that was used to determine the frequencies at which the half heights of a power resonance curve occur.) please I need some help I don't know how to proced.

2. Aug 26, 2016

### sophiecentaur

This is a homework / coursework question and should be in the appropriate forum. (Read the notice at the top of the forum list)
Also, before getting any help from PF you should show what you have done towards solving the problem. What does your "section 3.3" tell you?