Calculate the linear velocity of the Earth’s revolution around the sun if its orbital radius is 150 million km.

To calculate the linear velocity v of the Earth’s revolution around the Sun, it is necessary to divide the path traversed by the Earth in a year L by the time spent on this path t, that is, v = L: t.

Since the trajectory of the Earth’s motion can be taken approximately as a circle, then L = 2 ∙ π ∙ R, where π ≈ 3.14; R is the radius of the circle.

We get:

v = (2 ∙ π ∙ R): t.

The radius of the Earth’s orbit is 150 million km, that is, R = 1.5 ∙ 10 ^ 11 m, t = 1 year = 31536000 s. Let us find the average speed of the Earth’s orbital motion: v = (2 ∙ 3.14 ∙ 1.5 ∙ 10 ^ 11): (3.15 ∙ 10 ^ 7) ≈ 29904 m / s ≈ 30 km / s.

Answer: the speed of the Earth’s revolution around the Sun is ≈ 30 km / s.