Reviewing for the MCAT this Christmas, most of physics is going okay except I run into a few areas I was never familiar with to be begin with. 1. The problem statement, all variables and given/known data By what percentage does the frequency diminish in a horizontal spring mass system where k=1x10^3 N/m and m= 4 kg if the motion is dampened by a frictional force that has a damping coefficient of 2 kg/s? k=1000 N/m m = 4 kg W(d)=2 kg/s 2. Relevant equations w=sqrt(K/m) A=A(0)e-(b/2m)t w(d)=sqrt(w^2-(b/2m)^2) 3. The attempt at a solution Found omega by taking the square root of 1000/4, which is 15.81. From there I plugged that into my third equation, to give me b=126.12. Here is where I'm stuck and have been staring at this for over an hour. I know the solution is 0.0125% so I used that to work backward: 0.0125A(0)=A(0)e-(126.12/2*4)*t and found t to be 0.57 s. Thus, apparently if you solve for t you can solve for the percentage. But how the heck can you solve for t? No other harmonics equation gives me that number. Uhhhhgggg I never studied damped motion in HS OR college....google isn't helping, can someone else? EDIT: Okay. Just realized that if it's damped by 0.0125%, then I formatted my equation wrong to find time backwards. It should be .999875(0)=A(0)e-(126.12/2*4)*t t=7.93e-6 So this is the proper format I believe, however I'm no closer to solving for time without working backwards!! Help!