A car traveling westward at 20 m/s turns around and travels eastward at 15 m/s. If this takes place in 5 s, what is the average acceleration of the car

answeralert drivers who drift off the road;

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.