Currents during lightning strikes can be up to 50000 A (or more!). We can model such a strike as a 47500 A vertical current perpendicular to the earth's magnetic field, which is about 12 gauss.
a. What is the force on each meter of this current due to the earth's magnetic field?

57 N

Explanation:

Force on a current carrying conductor in a magnetic field

B = 12 X 10⁻⁴ T

= Bil where B is magnetic field , i is current and l is length of conductor

force required = 12 x10⁻⁴ x 47500 x 1

= 57 N

since you're a real machine, your ama is always less than your ima, because you can never totally eliminate friction.

i wanna say it’s between b and d, leaning more towards b.