Question

select the correct text in the passage.
which sentence best describes energy flow through a natural (not manmade) system?
a strong wind blows across a midwestern prairie. the wind forces the blades of a wind turbine to rotate. as the blades spin, the turbine converts mechanical energy to electrical energy. the electricity generated by the wind turbine is used to power nearby homes.

Explanation:

To determine the energy flow, we analyze the process:

1. The wind (which has kinetic energy due to its motion) blows across the prairie.
2. The wind’s kinetic energy is transferred to the wind turbine’s blades, causing them to rotate (so kinetic energy of wind → kinetic energy of turbine blades).
3. The rotating turbine converts its mechanical (kinetic) energy into electrical energy via electromagnetic induction.
4. The electrical energy is then used to power homes (electrical energy → various forms of energy like light, heat, mechanical in homes, but the core natural system energy flow here is wind (kinetic) → turbine (mechanical) → electricity (electrical)).

So the energy flow through the natural (and then human - made, but the natural part is wind to turbine) system is: Kinetic energy (of wind) → Mechanical energy (of turbine blades) → Electrical energy (from turbine). If we focus on the natural system (wind and turbine interaction before electricity is used in homes), it’s kinetic (wind) to mechanical (turbine).

If we consider the full chain including the turbine’s energy conversion (even though the turbine is man - made, the energy source is natural wind), the flow is wind’s kinetic energy → mechanical energy (turbine) → electrical energy.

Answer:

To determine the energy flow, we analyze the process:

1. The wind (which has kinetic energy due to its motion) blows across the prairie.
2. The wind’s kinetic energy is transferred to the wind turbine’s blades, causing them to rotate (so kinetic energy of wind → kinetic energy of turbine blades).
3. The rotating turbine converts its mechanical (kinetic) energy into electrical energy via electromagnetic induction.
4. The electrical energy is then used to power homes (electrical energy → various forms of energy like light, heat, mechanical in homes, but the core natural system energy flow here is wind (kinetic) → turbine (mechanical) → electricity (electrical)).

So the energy flow through the natural (and then human - made, but the natural part is wind to turbine) system is: Kinetic energy (of wind) → Mechanical energy (of turbine blades) → Electrical energy (from turbine). If we focus on the natural system (wind and turbine interaction before electricity is used in homes), it’s kinetic (wind) to mechanical (turbine).

If we consider the full chain including the turbine’s energy conversion (even though the turbine is man - made, the energy source is natural wind), the flow is wind’s kinetic energy → mechanical energy (turbine) → electrical energy.