A block of mass m = 850 g is released from rest and slides down a frictionless track of height 32.7 cm. At the bottom of the track, the block slides freely along a horizontal plane until it hits a spring with a constant of k = 50 N/m. What is the maximum compression of the spring that occurs?

50 inches should be the resultant vector

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.