Answer to Question #4565 in Astronomy | Astrophysics for Theresa

Question

Assuming that Earth has a circular orbit with a radius of 1.496 x 10^11 m, what is
a) the average speed (in m/s) o fEarth for one full orbit?
b) the average velocity of Earth for one full orbit?

Answer 1

We are given

a) Average speed defined the length of the path traveled until time t by the time.

length of the path is length of the orbit. Length of circular orbit relates with its radius as:

One full orbit Earth goes for one year. Hence:

Thus


Velocity is the measurement of the rate and direction of change in the position of an object. It is a vector physical quantity; both magnitude and direction are required to define it.
The scalar absolute value (magnitude) of velocity is speed.
b) The average velocity v of an object moving through a displacement delta x during a time interval (Δt) is described by the formula:

After rounding one full orbit Earth is back at its start position, so displacement is zero. Thus:

Answer: average velocity of Earth for one full orbit