An amount of work w is done on an object of mass m initially at rest, and as result it winds up moving at speed v. suppose instead it were already moving at speed v and the same amount of work w was done on it. what would be its final speed?

prndulum needs thread, weight clock to time swings

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.