Question

sandra sets identical magnetic carts on two tracks. at the end of each track is a large magnet that cannot move. she then moves the carts one space to the left or one space to the right. which movement will result in the largest increase in potential energy?
moving the cart on track 2 one space to the right (-->)
moving the cart on track 2 one space to the left (<--)
moving the cart on track 1 one space to the right (-->)
all of these movements will result in the same change in potential energy because they each move a cart the same distance.

Explanation:

Magnetic potential energy (for like - pole repulsion, as carts and end magnets likely have like poles) increases as the distance between the magnets decreases (since work is done against the repulsive force). The cart on Track 2 is initially farther from the end magnet. Moving it left (toward the end magnet) reduces the distance more significantly (compared to other movements) when considering the initial positions. Moving right would increase distance (decreasing PE), moving Track 1 cart right also increases distance (decreasing PE), and equal distance doesn't mean equal PE change as initial distances differ. So moving Track 2 cart left increases PE the most.

Answer:

Moving the cart on Track 2 one space to the left ( < -- )