You have a very thin $(40$ AWG$)$ and $8\mathrm{.}7$ cm long copper wire without insulation and you attach it to a power supply. What is the minimum current $($in Amps$)$ that you need to apply to this wire so that the magnetic force due to the Earth's magnetic field will be able to lift the wire up or overcome the wire's weight? $40$ awg wire has a mass per unit length of $4\mathrm{.}5*10^-5$ kg$/$m$.$ The horizontal component of earth's magnetic field at sea level in boston is about $20$ muT.