During the in richmond, the angle of the sun at noon from the vertical is 14 degrees (= richmond's latitude of 37.5 degrees minus earth's tilt of 23.5 degrees).

The answer is supposed to be during the summer in Richmond, the angle of the sun at noon from the vertical is 14 degrees which is equal to Richmond's latitude of 37.5 degrees minus Earth's slope of 23.5 degrees.  While in the winter, the angle of the sun at noon from the vertical is 61 degrees.

this could be newton#'s law of cooling. the cooling curve is exponential