A nucleus moving with a velocity →v emits anα-p article. Let the velocities of the α-particle and the remaining nucleus be →v1 and →v2 and their masses be m1, and m2.
A nucleus moving with a velocity →v emits anα-p article. Let the velocities of the α-particle and the remaining nucleus be →v1 and →v2 and their masses be m1, and m2.
,
and 
must be parallel to each other.
None of the two of 
,
and 
should be parallel to each other.
+ 
must be parallel to 
.
must be parallel to 
.
The correct option is D must be parallel to .
If initially the nucleus is moving with a velocity →v, then considering the nucleus as a point mass,
its centre of mass is moving with →v.
Now after the disintegration of nucleus into α-particle and the residual, the COM should be moving with the same velocity as there is no net external force acting upon it.
And we also know,
→vCM=m1→v1+m2→v2m1+m2
Which clearly shows that (m1→v1+m2→v2) must be parallel to →v.
must be parallel to .
If initially the nucleus is moving with a velocity →v, then considering the nucleus as a point mass,
its centre of mass is moving with →v.
Now after the disintegration of nucleus into α-particle and the residual, the COM should be moving with the same velocity as there is no net external force acting upon it.
And we also know,
→vCM=m1→v1+m2→v2m1+m2
Which clearly shows that (m1→v1+m2→v2) must be parallel to →v.
