What will be the escape speed from a planet having mass 16 times that of earth and diameter 8 times that of the earth ? `(v_(e)=11.2 "kms"^(-1))`

Options

A. `12.82 "kms"^(-1)`
B. `15.84 "km s"^(-1)`
C. `13.85 "km s"^(-1)`
D. `10.54 "km s"^(-1)`

Answer

B

Explanation

`v=sqrt((2GM)/(R))`
`:. (v_(p))/(v_(e))=sqrt((M_(p))/(M_(e))xx(R_(e))/(R_(p)))=sqrt((16 M_(e))/(M_(e))xx(R_(e))/(8R_(p)))`
`:. v_(p)=sqrt(2)v_(e)=sqrt(2)xx11.2=15.84 "kms"^(-1)`