The escape velocity for a body projected vertically upwards from the surface of the earth is `11.2 km s^(-1)`. If the body is projected in a direction making an angle `45^@` with the vertical, the escape velocity will be

Options

A. `11.2/(sqrt(2))kms^(-1)`
B. `11.2xxsqrt(2)kms^(-1)`
C. `11.2xx2kms^-1`
D. `11.2kms^-1`

Answer

D

Explanation

Change in energy `=1/(2(GMm)//R)=1//2Mv_(e)^(2)`
So, it is independent of angle as gravitational field is conservative in nature.