#### a) The average distance between the Earth and the Sun is 10^{8} km. Calculate the average speed of the Earth in its orbit in kilometers per second.

#### b) What is this is meters per second?

**Solution:**

### Part a

We assume that the earth revolves around the sun in a circular manner. Therefore, the distance between the earth and the sun will be the radius of its orbit.

The total distance traveled the earth in full revolution is

The total time of travel is

Therefore, the average speed is

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Therefore, the average velocity of the earth is 19.91 km/s.

### Part b

Convert 19.91 km/s to m/s.

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Therefore, the velocity is 19910 m/s.