A 1 meter long rod on the ice with mass m2=1 kg is perpendicularly hit on one end by a point particle with mass m1=0.1 kg. The collision is elastic and the point particle is bounced back in the same direction. After the collision the rod's frequency is ν=2 Hz. What was the initial velocity of the point particle?
My attempt:
Since the collision is elastic, the kinetic energy of the system is the same before and after the collision: 0.5m1v21=0.5J2ω22+0.5m2v22+0.5m1v23
Where v3 is the velocity of the point particle after the collision.
Now, in the case of a rod: J=112L2m
And, we also know: ω2=2πν
And there are also no external forces, therefor the momentum of the system is the same before and after the collision: m1→v1=m1→v3+m2→v2
Here v1 is the quantity we're looking for, v3 is the point particle's velocity after the collision and v2 is the velocity of the rod's center of mass. It follows: →v2=m1→v1−m1→v3m2
From this it follows: 0.5m1v21=124L2m24π2ν2+0.5m2|m1→v1−m1→v3m2|2+m1v23
This is 1 equation with 2 unknowns, and this is where I get stuck. Any help is appreciated.
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