Infer whether a system can have kinetic energy and potential energy at the same time.

hmm as for this, it can happen, but for a very small moment so, it is considered to not actually work, considering that kinetic and potential energy are actually opposites so... I would have to say for this one your answer is no

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-- FTS

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.