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:
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