The discussion focuses on calculating the level of damping in a torsional pendulum using the logarithmic decrement formula. The amplitude of the vibration decreases such that the amplitude on the 100th cycle is 13% of the initial amplitude. The correct calculation for the logarithmic decrement is δ = (1/n) * ln(xo/xn), where n is 100, xo is the initial amplitude, and xn is the amplitude after 100 cycles. The correct logarithmic decrement value is 2.04, derived from ln(100/13).
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Level of damping δ = 1/n*ln(xo/xn)tone999 said: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.
Is this simply ln(100/13)= 2.04
or ln(13/100)= -2.04?