Q11DQ

Question

Why is the earth only approximately an inertial reference frame?

Step-by-Step Solution

Verified
Answer

Earth is not considered to be a perfect inertial reference frame because of the small effect of the earth’s rotational motion and the motion around the sun. 

1Step 1: Newton’s First law

According to this law, a body will retain its state of rest or of uniform motion until an external force is applied.

2Step 2: Inertial frame of reference.

A non-accelerating reference frame is known as inertial reference frame.  The time period of revolution of earth in its orbit remains constant but this does not mean that earth moves with a constant velocity. As the orbit of earth is elliptical with sun on one of its focus, the velocity of earth in its orbit keeps varying. Thus, earth is only approximately an inertial reference frame.