Physics

Problem

The Earth orbits the Sun at an average speed of about

30 \text{ kms}^{-1}

. Neptune orbits the Sun with an orbital radius 30 times greater than the Earth's. The best estimate for the orbital speed of Neptune is a.

1.0 \text{ kms}^{-1}

2.7 \text{ kms}^{-1}

5.4 \text{ kms}^{-1}

7.2 \text{ kms}^{-1}