Calculate both the repulsive and gravitational force between a he atom and a b atom that are 7x10^-15m apart from one another?

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .

real, smaller and upside-down.   so the answer should be b.

he made 11 calls in one day

f=ma newton

f=100x2.5=250n