Answer
given,
length of bar = 80 cm
mass of the bar = 10 kg
smaller mass = 4 kg
distance = 20 cm


taking moment about B






difference between two scale = 8 - 6
= 2 N
F = q₁q₂C / r²
F force
q charge
C Coulomb constant
r separation between charges
no BECQUSE POSUM BROOB SHSHSJ
Because it does not produce waste, thus it doesn't harm the environment. also renewable sources are infinite.