Final answer:
To experience a magnetic field less than the Earth's field, a person must be at least 60,000 meters away from the starter cable.
Step-by-step explanation:
The distance at which a person will experience a magnetic field less than the Earth's field can be calculated using the formula:
B = (μ0 ⋅ I)/(2π⋅r)
where B is the magnetic field, μ0 is the permeability of free space, I am the current flowing through the wire, and r is the distance from the wire.
Since we want the magnetic field to be less than the Earth's field, we can set the inequality:
B < 5.00⋅10-5 T
Substituting the known values, we have:
(μ0⋅ I)/(2π⋅r) < 5.00⋅10-5 T
By rearranging the formula and solving for r, we can find the minimum distance:
r > (μ0 ⋅ I)/ (2π⋅5.00⋅-5 T)
Substituting the values, we have:
r > (4π⋅ (150 A))/ (2π⋅5.00⋅-5 T)
r > 60,000 m
Therefore, a person must be at least 60,000 meters away from the starter cable in order to experience a magnetic field less than the Earth's field.