In the rock-tumbling scenario, what energy transformation is primarily occurring as the rock speeds up downhill?

In the rock-tumbling scenario, what energy transformation is primarily occurring as the rock speeds up downhill?

• A. Gravitational potential energy is converted to kinetic energy
• B. Kinetic energy is converted to gravitational potential energy
• C. Gravity converts to chemical energy
• D. Thermal energy is the primary energy source

Answer: (A)

When the rock speeds up downhill, gravity is doing work on it. The rock’s gravitational potential energy, which depends on height, decreases as it lowers, and that energy is converted into kinetic energy, the energy of motion. In simple terms, mgh turns into (1/2)mv^2 as the rock accelerates. If some energy becomes heat due to friction or air resistance, that’s a secondary byproduct, but the main transformation causing the speeding up is gravitational potential energy changing into kinetic energy. The other ideas don’t fit: kinetic energy isn’t being turned into potential to make it go faster downhill, gravity isn’t converting to chemical energy, and heat isn’t the primary source driving the speed.

When the rock speeds up downhill, gravity is doing work on it. The rock’s gravitational potential energy, which depends on height, decreases as it lowers, and that energy is converted into kinetic energy, the energy of motion. In simple terms, mgh turns into (1/2)mv^2 as the rock accelerates. If some energy becomes heat due to friction or air resistance, that’s a secondary byproduct, but the main transformation causing the speeding up is gravitational potential energy changing into kinetic energy. The other ideas don’t fit: kinetic energy isn’t being turned into potential to make it go faster downhill, gravity isn’t converting to chemical energy, and heat isn’t the primary source driving the speed.