Final answer:
Permanent magnets in a starter motor are crucial for converting electrical energy into the mechanical work needed to start a vehicle's engine by exerting torque on coils of wire within the magnetic field.
Step-by-step explanation:
Permanent magnets are a critical component of the starter motor in vehicles.
The starter motor uses these magnets in combination with coils of wire to convert electrical energy into mechanical work, which is used to start the engine. When a current is passed through the loops of wire within the magnetic field, the magnetic force exerts torque on the loops, causing the motor's shaft to rotate. This rotation is essential for engaging the engine's flywheel, thereby starting the internal combustion process. To maintain steady rotation, a commutator in the starter motor reverses the current direction at specific intervals, ensuring continuous torque and movement.