Final answer:
To determine the distance from a car starter cable carrying 150 A to experience a magnetic field less than Earth's, we calculate using the formula for the magnetic field around a long straight conductor.
Step-by-step explanation:
The question is related to magnetic fields generated by electrical conductors and the physics of how these fields can be calculated. In answering the question how far from the starter cable of a car, carrying 150 A, must you be to experience a field less than the Earth's magnetic field (5.00 × 10^-5 T), we use the Ampere's Law or Biot-Savart Law which relates the magnetic field around a long straight conductor to the current it carries.
The formula for the magnetic field at distance r from a straight wire carrying current I is B = (μ0 * I) / (2π * r), where μ0 is the permeability of free space (4π × 10^-7 T*m/A). We set B to less than 5.00 × 10^-5 T and solve for r to find the distance needed.