Class 12 NEET Physics Atoms and Nuclei Questions Part 2

Momentum of emitted photon =pphoton=

hυ

c

From the law of conservation of linear momentum.
Momentum of recoil nucleus =pnucleus=pphoton
∴Mv=

hυ

c

where v is the recoil speed of the nucleus
or v=

hυ

Mc

..........(i)
The recoil energy of the nucleus
=

1

2

Mv2=

1

2

M(

hυ

Mc

)2=

h2υ2

2Mc2

 (Using (i))