Two masses connected by a spring on frictionless track

[don_anon25]

Please help with this! Harmonic Motion

Two masses m1=100 g and m2=100 g slide freely in a horizontal frictionless track and are connected by a spring whose force constant is k=.5 N/m. Find the frequency of oscillatory motion for this system. I know omega = sqrt (k/m), but I have two masses, rather than just one. How does this work? Could someone give me an idea of how I should go about solving this?

Thanks!

 

[lightgrav]

there's a place in the spring which doesn't move (the center-of-mass).
so each side of the spring stretches independently, with a new k.