A farmer has enough food to feed 20 animals in his cattle for 6 days.How would the food last if there were 10 more animals in his cattle?

The earth's surface has-a negative surface charge density of 10^(-9) Cm^(-2) . The potential difference of 400kV between the top of the atmosphere and the surface results in a current of only 1800A over the entire globe. If there were no mechanism of sustaining atmospheric electric field, how much time would be required to neutralize the earth's surface charge? Take radius of earth = 6.37xx 10^(6) m.