The north and south poles of two magnets are attached to each other. A student pulls the poles apart and holds them at a distance of 10 cm. How does the energy stored in the system change?
A. Then energy stored in the system decreases.
B. The energy stored in the system first increases and then decreases.
C. The energy stored in the system does not change.
D. The energy stored in the system increases.
B. The energy stored in the system first increases and then decreases.
When the north and south poles of two magnets are attached to each other, they have potential energy stored in them due to their magnetic attraction. When the student pulls the poles apart, they do work to overcome this attraction and increase the potential energy of the system. The energy stored in the system increases as the poles are pulled apart to a distance of 10 cm. However, if the student releases the poles, they will come back together due to the magnetic attraction, which will cause the potential energy of the system to decrease. Therefore, the energy stored in the system first increases and then decreases.
To determine how the energy stored in the system changes when the north and south poles of two magnets are pulled apart and held at a distance of 10 cm, we need to understand the concept of magnetic potential energy.
The magnetic potential energy between two magnets is inversely proportional to the square of the distance between their poles. As the distance between the magnets increases, the magnetic potential energy decreases.
In this scenario, when the student pulls the poles apart and holds them at a distance of 10 cm, the distance between the magnets' poles has increased. Therefore, the magnetic potential energy of the system decreases.
Hence, the correct answer is A. The energy stored in the system decreases.
The correct answer is A. The energy stored in the system decreases.
When the north and south poles of two magnets are attached, they are in a state of magnetic potential energy. This energy is released when the magnets are pulled apart. As the student pulls the poles apart and holds them at a distance of 10 cm, the magnets lose their potential energy because they are further apart and have weaker magnetic interactions. Therefore, the energy stored in the system decreases.