- #1
Saitama
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Homework Statement
Two small identical discs, each of mass ##m##, lie on a smooth horizontal plane. The discs are interconnected by a light non-deformed spring of length ##l_0## and stiffness ##k##. At a certain moment one of the discs is set in motion in a horizontal direction perpendicular to the spring with velocity ##v_0##. Find the maximum elongation of the spring in the process of motion, if it is known to be considerably less than unity.
(Answer: ##mv_0^2/(kl_0^2)##)
Homework Equations
The Attempt at a Solution
I don't really know how should I begin here. Writing down the differential equation for the motion seems to be complicated. A hint follows the given answer stating that the problem is easier to solve in frame of centre of inertia. I don't see how can I utilize this to solve the problem. I mean, I can find ##v_{CM}## at t=0, then I guess I have to use conservation of energy. But how do I calculate the initial energy here? Do I have to calculate the relative velocities of discs w.r.t CM to find the energy (this is a guess)?