Explain when there is a change in the length of a solar day.
Time interval between two successive transits of a given meridian by the mean sun is called mean solar day. It is generally close to 24 hours, or the length of a day. The length of the solar day keeps changing throughout the year.
Now, the change in the solar time occurs due to the combination of reasons like the eccentricity of the orbit, the varying speed of earth's motion around the sun, the apparent shift in sun's potions in the sky.
If the earth's rotation were to be reversed then the length of the solar day would decrease and the earth would rotate faster on its own axis with respect to the sun then compared to the stars.