Q: Many natural rock formations change color over time. In Utah, for example, iron oxidized and formed red, orange, and yellow rock. Which of the following is the cause of this change? ---- OPTIONS:
- chemical weathering
- mechanical weathering
- water erosion
- wind erosion

A: chemical weathering

Q: How much time is required for a bicycle to travel a distance of 100 m at an average speed of 2 m/s? ---- OPTIONS:
- 0.0
- s B 50 s
- 100 s
- 200 s

A: s B 50 s

Q: Wind turbines are being used to generate electricity in many parts of the United States. One advantage of wind turbines is that no fossil fuels are burned. Which of the following is a disadvantage of wind turbines? ---- OPTIONS:
- Wind turbines can emit dangerous radiation if damaged.
- Wind turbine farms must be located near large bodies of water.
- Wind turbines do not produce energy until many years after being built.
- Wind turbine farms require a lot of area compared to how much energy they produce.

A: Wind turbine farms require a lot of area compared to how much energy they produce.

Q: Why do scientists perform multiple trials of the same experiment? ---- OPTIONS:
- to include additional variables in the experiment
- to complete the steps of the experiment in less time
- to find a less expensive way to conduct the experiment
- to increase the likelihood of accurate experiment results
A: to increase the likelihood of accurate experiment results