Question

A bar magnet is held in place while another bar magnet is placed near it. The second bar magnet spins around and attaches to the first magnet on one end. Which statement is correct about the energy stored in the magnetic field? (1 point)
Responses

The decrease in the energy stored in the system is proportional to the decrease in kinetic energy.
The decrease in the energy stored in the system is proportional to the decrease in kinetic energy.

The increase in the energy stored in the system is proportional to the decrease in kinetic energy.
The increase in the energy stored in the system is proportional to the decrease in kinetic energy.

The increase in the energy stored in the system is proportional to the increase in kinetic energy.
The increase in the energy stored in the system is proportional to the increase in kinetic energy.

The decrease in the energy stored in the system is proportional to the increase in kinetic energy.
The decrease in the energy stored in the system is proportional to the increase in kinetic energy.

Answer 1

"The decrease in the energy stored in the system is proportional to the increase in kinetic energy."

Reason: As the magnets attract, magnetic potential energy (energy in the field) decreases and that released energy becomes the kinetic energy of the moving magnet (ΔU_field < 0 ⇒ ΔK > 0).