Question

To determine which statement is true according to the bar graph (not provided), we need to consider the principles of energy conservation in a roller coaster system, which involves both potential and kinetic energy.

1. **Potential Energy:** This energy is highest at the top of the roller coaster (e.g., locations A or C) where the height is greatest.
2. **Kinetic Energy:** This energy is highest at the lowest points of the roller coaster (e.g., locations B or D) where the speed is greatest.

In a perfect roller coaster with no friction or energy loss:
- As the coaster descends from a height, potential energy is converted into kinetic energy.
- As it ascends, kinetic energy is converted back into potential energy.
- The total energy of the system remains constant if we neglect friction and air resistance.

Now, let's analyze the statements:

1. **The roller coaster creates potential energy, but kinetic energy does not change.**
- This is not true because potential and kinetic energy convert into each other.

2. **The roller coaster destroys potential energy.**
- This is not true, as energy can't be created or destroyed; it changes form.

3. **The roller coaster creates kinetic energy.**
- This is not true because kinetic energy is gained from the conversion of potential energy, not created.

4. **Both potential and kinetic energy change, but total energy does not change.**
- This statement aligns with the law of conservation of energy, where energy changes forms but the total remains constant.

Based on this analysis, the true statement is **"Both potential and kinetic energy change, but total energy does not change."**