People have proposed driving motors with the earth's magnetic field. this is possible in principle, but the small field means that unrealistically large currents are needed to produce noticeable torques. suppose a 16-cm-diameter loop of wire is oriented for maximum torque in the earth's field.

what current would it need to carry in order to experience a very modest 1.0�10? 3n? m torque?

I_max= 1000 A

Explanation:

Expression of torque is given by

τ= BIA Sinθ

B= strength of magnetic field

I= current

A= Area

for maximum torque θ=90°⇒sin 90=1

Now for I_max= τ/BA

Let us take the average magnetic field of the earth as 50μT.

Area is calculated as

Substitute the values and calculate for maximum current

I_max= 1000 A

well, you would divide 135 by 33 to get your answer. then that is how many seconds it would take. boardman should fly about 132 m or 4.090909090909091 seconds.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.