Question
An alpha nucleus of energy bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to
v2
1/ m
1/ν4
1/ Ze
Solution
B.
1/ m
Since, here nuclear target is heavy it can be assumed safely that it will remain stationary and will not move due to the Coulombic interaction force.
At distance of closest approach relative velocity of two particles is v. Here target is considered as stationary, so a-particle comes to rest instantaneously at distance of closest approach. Let the required distance is 'r' then from work energy-theorem.
The change in kinetic energy of a particle is equal to the work done on it by the net force.
