Physical weathering can be for example freezing and thawing cycles which can force open cracks or fractures in the rocks which can then make those rocks more susceptible to chemical weathering. This is the most obvious example of physical weathering.
A renewable energy source is a natural resource on Earth that can be naturally replenished in a short period of time. Wind is considered clean and renewable because it will not produce harmful pollutants or emissions and won't harm our ecosystem!
