1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution I find this task very hard to understand. First of all, when adding more mass, wouldn't that change the acceleration, according to F=ma? And in that case the velocity should also change when adding more mass, shouldn't it? That would then also change the amplitude and angular frequency. When I think of it intuitively, I think that adding more mass will increase the inertia, and hence make the amplitude less and also the frequency. Why is this wrong? I don't understand how to think about the physical concepts in this example. If you understand it, please explain how you reason about it!