Earth's atmosphere is constantly bombarded by cosmic ray protons that originate somewhere in space. If the protons all passed through the atmosphere, each square meter of Earth's surface would intercept protons at the average rate of 1500 protons per second. What would be the electric current in amperes intercepted by a 28 * 107 km2 area on the planet?

0.0672 A

Explanation:

The average rate of the intercepted protons is 1500 protons/s. The charge of a proton is equivalent to + e which is 1.6*10^-19 C. The electric current (i) can be calculated using the formula below:

i = area*number of protons*charge of proton

Where:

area = 28*10^7 km^2 = 28*10^ (7+6) m^2 = 28*10^13 m^2

i = 28*10^13 * 1500 * 1.6*10^-19 = 0.0672 A

The electric current intercepted is equal to 0.0672 A