Does anybody know about free fall for physics

61.74 m/s

Explanation: Use the first equation for free falling bodies

a = vf - vi / t

Derive for vf:

vf = at + vi ( vi = 0 since it starts from rest)

Substitute the values

vf = 9.8 m/s² x 6.3 s

= 61.74 m/s

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 .