Register to reply

Torsional pendulum, logarithmic decrement

Share this thread:
Jul21-09, 06:33 PM
P: 18
1. The problem statement, all variables and given/known data

The amplitude of a torsional vibration decreases so that the amplitude on the 100th cycle is 13% of the the amplitude of the first cycle. Determine the level of damping in terms of the logarithmic decrement.

2. Relevant equations

3. The attempt at a solution

Is this simply ln(100/13)= 2.04

or ln(13/100)= -2.04?
Phys.Org News Partner Science news on
'Office life' of bacteria may be their weak spot
Lunar explorers will walk at higher speeds than thought
Philips introduces BlueTouch, PulseRelief control for pain relief
Jul22-09, 07:48 AM
Redbelly98's Avatar
P: 12,074
It will be a positive number (use 100/13, not 13/100). However, you still need to account for the fact that it takes 100 cycles to reach 13%.

Register to reply

Related Discussions
Torsional Pendulum, Logarithmic Decrement Introductory Physics Homework 1
Torsional Vibration Mechanical Engineering 3
Axial, torsional and pendulum modes of vibration(harmonic motion) Introductory Physics Homework 0
Torsional vibrations Engineering, Comp Sci, & Technology Homework 0
Torsional waves? General Physics 3