How come more coils on a slinky make the velocity higher ?

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer

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