Question

determine work required to assemble one alpha particle at each corner of a square of side 1m.

Answer 1

when no particle is there, work done =0 (ofcorse)
now when you bring 2nd, 3rd and 4th partcile,some work would be required,eqch different.
you need to write all possible combinations of interactions of charges
W12 = k. Q^2 / 1
similarly, you'll be required to calculate
W13, W14 , W23 ,W24 , W34

add all together in the end..

Answer 2

thanks

Answer 3

glad i could help :)