Why does fast working machine posses more power​

Power is the energy input per unit time. ... Therefore, if the more powerful train can go twice as fast as the less powerful train, it takes half as long, but requires 16 times more power to move at that speed.

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

the rearrangement of particles in a physical change. hope this