The grass has more friction. The grass attracts more wind. The grass has a higher temperature. The grass increases Earth's gravity.
I gave my students this multiple choice question: Christina kicks a ball. The ball moves faster when she kicks it on the concrete sidewalk than when she kicks it on the grass. Why does the ball travel slower on the grass than the sidewalk?

Only one answer is correct among these 4 choices:
- The grass has more friction.
- The grass attracts more wind.
- The grass has a higher temperature.
- The grass increases Earth's gravity.

Could you tell me which one is correct?

The grass has more friction.