Here is the solution for question two which say that "A 0.200 kg mass on a spring executes simple harmonic motion at a frequency of f. What mass is necessary for the system to vibrate at a frequency of 2f?"

 

Solution: Let f = 1 and solve for K. Then, give f a value of 2 because the frequency double and solve for m using the previously calculated k value. M should be equal to 0.05kg. Try it and I'll break it down some more for you tomorrow. Good luck!