Let velocity before collision v from momentum conservation mv=(m+m)v1
v1=2v
Loss in K.E. =21mv2−21(2m)(2v)2
=41mv2
K.E. lost is used to jump from 1st orbit to 2nd orbit ΔK.E.=10.2eV
⇒41mv2=10.2
21mv2=2×10.2=20.4eV
JEE Main 2016 — Physics Modern Physics
A neutron moving with a speed 'v' makes a head on collision with a stationary hydrogen atom in ground state. The minimum kinetic energy of the neutron for which perfactly inelastic collision will take place is :
Held on 10 Apr 2016 · Verified 6 Jul 2026.
20.4 eV
10.2 eV
12.1 eV
16.8 eV
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