Question

Airplanes and trains move through the earth's magnetic field at rather high speeds, so it is reasonable to wonder whether this field can have a substantial effect on them. We shall use a typical value of 0.50 G for the earth's field.
A) The French TGV train and Japanese "bullet train" reach speeds of up to 180 mph with wheels moving on tracks about 1.5 m apart. At top speed moving perpendicular to the earth’s magnetic field, what potential difference is induced across the tracks as the wheels roll?
B) Does this seem large enough to produce noticeable effects?
Yes, this potential difference seems large enough to cause noticeable effects.
No, this potential difference is much too small to be noticeable.
C) The Boeing 747-400 series of aircraft has a wingspan of 64.4 m and a cruising speed of 565 mph. If there is no wind blowing (so that this is also their speed relative to the ground),what is the maximum potential difference that could be induced between the opposite tips of the wings?
D) Does this seem large enough to cause problems with the plane?
Yes, this potential difference seems large enough to cause noticeable effects.
No, this potential difference is too small to be noticeable.

Answer 1

Answer:

b

Explanation:

Answer 2

Answer:

a)    ΔV = 60.4 V , c)   ΔV = 8130.5 V

Explanation:

A) For this problem we must find the induced electromotive force (fem), in this case the electric force and the magnetic force have opposite directions

         $F_{e}$ = $F_{m}$

         qE = q vB

          E = ΔV / L = v B

         ΔV = v L B

Let's reduce the magnitudes to the SI system

         v = 180 mph (1609 m / 1 mile) (1h / 3600s) = 80.5 m / s

        ΔV = 80.5 1.5 0.5

        ΔV = 60.4 V

B) This voltage is indexed throughout the train anchi, so even though it is a voltage that can produce notable effects, the correct answer is Yes

C)  Let's reduce speed

       v = 565 mph = 252.5 m / s

Let's calculate

         ΔV = 60.4 V V = 252.5 64.4 0.5

         ΔV = 8130.5 V

D) Yes, I could believe the problem in the electronics of the plane, but remember that the plane is in a Faraday cage and this load is on its surface, so the inside does not feel its effects,