A body is projected vertically upwards from the surface of the earth with a velocity equal to half the escape velocity. If R is the radius of the earth , maximum height attained by the body from the surface of the earth is :

Question

$$\begin {array} {1 1} (1)\;\frac{R}{6} & \quad (2)\;\frac{R}{3} \\ (3)\;\frac{2R}{3} & \quad (4)\;R \end {array}$$