1. From a cord of length L = 0.877m hangs a 1.7Kg mass. The mass swings through an angle of +/- _max,0 = 13.1^o intially, but 1.88s later the amplitude of oscillation has been reduced through friction to a swing of amplitude _max,f = 5.15^o. Calculate the value of b/2m.

2. A manhole cover of mass m = 12.8kg is attached to the end of a k = 2260kg/s² spring. The damping coefficient is b = 3.55 kg/s. (a) Determine the angular frequency of oscillation and (b) How long before the energy of the system decreases by 10%?