Answer to Question #76174 in Classical Mechanics for nick barba

Question

A 85.0-kg daredevil exhibitionist hangs on to the end of a long bungee cord attached to the railing of the Brooklyn Bridge and oscillates vertically. (Do NOT try this!) The spring constant of the bungee cord is 131 N/m, and the system\'s damping constant is 0.128 kg/s. How long does it take for the oscillation amplitude to decrease to 94.9% of its initial value?

Answer 1

0.915 = e^[-bt/2m]
ln(0.949) = -(0.128 kg/s)(t)/[2(85.0 kg)]
t = 69.5 s