Planet Z has the same average density as Earth

PHYSICS · Single correct · CBSE · Physics · Gravitation · Gravitation

Problem

Planet Z has the same average density as Earth. If the escape speed from Planet Z’s surface equals Earth’s orbital speed around the Sun (

30\,\text{km}\,\text{s}^{-1}

), the radius of Planet Z in terms of Earth’s radius

R_{\oplus}

is closest to (a)

3.6\,R_{\oplus}

(b)

2.7\,R_{\oplus}

(c)

1.9\,R_{\oplus}

(d)

5.0\,R_{\oplus}