Chapter 15, Problem 90A

To determine

The Sun’s motion if the light coming from a point on its left edge has a slightly higher frequency than the light from the right edge.

Explanation of Solution

Introduction:

The frequency of wave varies when the source and observer move towards or away from each other. This effect on frequency is known as Doppler effect.

The Doppler effect occurs for both mechanical and electromagnetic wave motion.

The frequency perceived by a detector is morethan that of the source when the source moves towards the detector, whereas, frequency perceived by a detector is less than that of the source if the source moves away from the detector. This implies that the left side of the Sun is towards the Earth and the right side is away from it. Thus, it can be assumed the Sun must be rotating in the same manner as the Earth.

Conclusion:

Thus, the left side of the Sun is towards the Earth and the right side is away from it. The Sun must be rotating in the same manner as Earth.