Which car has the most kinetic energy? a car of mass 1500 kg with speed 5 m/s or a car of mass 1300 kg with speed 3 m/s or a car of mass 1200 kg with speed 2 m/s or a car mass 1400 kg with speed 4 m/s

3. dark matter

empty space could also be a simple vacuum

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.