What variables can affect the performance of a marathon runner?

Air temperature and performance are significantly correlated through a quadratic model. The optimal temperatures for maximal mean speed of all runners vary depending on the performance level. When temperature increases above these optima, running speed decreases and withdrawal rates increase.

Explanation:

explanation:

the sun shines white and black light to our planet. the white light has all the colors in it. in our upper atmosphere, we have dust particles and oxygen molecules. the white light meaning all of the colors in a rainbow shines through the upper levels of the atmopshere and the blue light scatters across the entire planet. that is why our sky is blue.