Final answer:
The sun's declination on July 20 will be slightly less than 23° N but still relatively close to this value since it's about a month after the summer solstice. Exact figures would require an ephemeris or astronomical software for precise calculations.
Step-by-step explanation:
The student is asking about the sun's declination on July 20. Declination is a measure of how far north or south an object is from the celestial equator, which is the projection of Earth's equator into space. During the summer solstice, which occurs on or about June 21, the declination of the sun reaches its maximum at 23° N, which corresponds with the Tropic of Cancer. This is when the sun is directly overhead at noon for observers located on this line of latitude.
The sun's declination changes gradually each day as Earth orbits around the sun. Since July 20 is about a month after the summer solstice, the declination will have decreased slightly from this maximum value. While I cannot give you an exact figure without more detailed astronomical calculations or data, based on the Earth's axial tilt and the time of year, the declination on July 20 would be less than 23° N but still fairly close to this value.
Therefore, what will the sun's declination be on the following date, July 20? It will be slightly less than 23° N. The precise value would require consulting an ephemeris or using astronomical software to calculate the exact position of the sun on that date.