The escape velocity of a body on the surface of the earth is `11.2km//s`. If the earth's mass increases to twice its present value and the radius of the earth becomeshalf, the escape velocity would become

Options

A. 5.6 km/sec
B. 11.2 km/sec
C. 22.4km/sec
D. 44.8km/sec

Answer

C

Explanation

`v_(e)=sqrt((2GM)/(R)),v'_(e)=sqrt((2G2M))/(R//2)=2sqrt((2GM)/(R))`
`v_(e)=2(11.2km//sec)=22.4km//sec`