An object has an acceleration of 12.0 m/s/s. If the mass of this object were doubled (with no change in its net force),
then its new acceleration would be m/s/s.

you can cut your hand off if your not

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.