[SOLVED] Dampened Harmonic Motion 1. The problem statement, all variables and given/known data A mass M is suspended from a spring and oscillates with a period of 0.900 s. Each complete oscillation results in an amplitude reduction of a factor of 0.985 due to a small velocity dependent frictional effect. Calculate the time it takes for the total energy of the oscillator to decrease to 50 percent of its initial value. HINT: The amplitude after N oscillations=(initial amplitude)x(factor)^N. 2. Relevant equations Newton's Second Law dampened- F=-kx-bv x(t)=Ae^(-bt/2m)cos((dw/dt)t) Energy=1/2kA^2 OR 1/2kv^2 [NOT constant] 3. The attempt at a solution Alright, I am having a difficult time setting this problem up. I do not know how to use the hint either... So far, I have set it up this way: F=-kx-bv The integral of this is equal to work. Negative work is equal to KE. -1/2kx^2+1/2bv^2=1/2kv^2 I realized that this is as far as I can get with this, so I tried to use the x(t) equation. However, we are not given a value for the mass. I am very frustrated right now so any direction you can give would be very much appreciated.