What is a definition of a neutrino and what purpose do Muon and Tau leptons have (including the neutrino versions)?

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.