Ok, I'm stuck again..... A block of mass M1=0.490 kg sits on a block with a mass of M2=4.50 kg that rests on a frictionless surface and is connected to a spring. The spring has a spring constant of k=16.6 N/m. The block is displaced and undergoes Simple Harmonic Motion. What is the largest amplitude (in meters) the block can have for the smaller block to remain at rest, relative to the larger block? The coefficient of friction between the two blocks is m=0.300 Ok so I tried like 5 different ways to work the problem and I know at least one of the ways I tried was wrong. I was working with F=ma. I was using a=g (acceleration=gravity) and so F=mg, and also mg=kx. I found my force (44.15 N) and multiplied it by my friction coefficient (0.300) and got 13.245 N so then I divide by my spring constant and get 0.79789 m. Which is wrong. My question is "What am I doing wrong and how do I fix this problem? Thanks abunch.