Question

a roller coaster car reaches its highest point on the track. at this moment, which energy transformation is about to occur?
potential energy will convert to kinetic energy
kinetic energy will convert to potential energy
all energy will be lost to friction
both energies will remain constant

a magnet and a piece of iron are moved closer together. what happens to the potential energy in this system?
potential energy decreases because they attract
potential energy increases because they attract
potential energy only changes if they touch
potential energy stays the same regardless of distance

Explanation:

First Question (Roller Coaster Energy Transformation)

At the highest point of a roller coaster, the car has maximum gravitational potential energy (due to height) and minimum kinetic energy (speed is low or zero at the peak). As it moves down from this point, the height decreases (so potential energy decreases) and speed increases (kinetic energy increases). Thus, potential energy is converted to kinetic energy. The other options are incorrect: kinetic to potential happens when moving up, energy isn’t all lost to friction (friction causes some loss but not all), and energies don’t remain constant as the car moves from the peak.

Second Question (Magnet and Iron Potential Energy)

A magnet and iron attract each other. When objects that attract are moved closer, the potential energy of the system decreases (similar to how gravitational potential energy decreases when a mass is moved closer to Earth). If they repelled, moving closer would increase potential energy, but here they attract. The other options are wrong: attraction leads to decreasing potential energy when moving closer, potential energy changes with distance (not just when touching), and it does not stay the same with distance.

Answer:

Potential energy will convert to kinetic energy