Two donut-shaped magnets are stacked on top of each other with a wooden dowel in the center. The south poles of the magnets are facing each other. Once the upper magnet is released, it accelerates downward and stops 1 cm above the lower magnet. How does the energy stored in the magnetic field change? (1 point)

a. Some of the energy stored is converted into kinetic, thermal, and gravitational energy.

b. Some of the energy stored is converted into kinetic and thermal energy.

c. All of the energy stored is converted into kinetic and thermal energy.

d. All of the energy stored is converted into kinetic, thermal, and gravitational energy.

whats the answer

its B

b. Some of the energy stored is converted into kinetic and thermal energy.

To determine how the energy stored in the magnetic field changes, we can consider the behavior of the magnets and the forces involved in this scenario.

When the upper magnet is released and accelerates downward, it experiences a change in potential energy due to the force exerted by the magnetic field. As the upper magnet moves closer to the lower magnet, the magnetic field between them becomes stronger, increasing the potential energy stored in the magnetic field.

However, once the upper magnet stops 1 cm above the lower magnet, the magnetic forces are balanced by the force of gravity pulling the magnet downward. At this point, the potential energy stored in the magnetic field reaches its maximum value. At the same time, the kinetic energy of the upper magnet is at its maximum as it is moving at its fastest speed.

So, as the upper magnet stops and remains in equilibrium above the lower magnet, the energy stored in the magnetic field does not change any further. Rather, some of the initial potential energy stored in the magnetic field is converted into kinetic energy, as the upper magnet accelerates downward, and some of it is also converted into thermal energy due to any friction or resistance in the system.

Therefore, the correct answer is:

b. Some of the energy stored is converted into kinetic and thermal energy.