A particle is projected from the surface of earth with an initial speed of 4 km/s . Find the maximum height attained by the particle.Radius of earth =6400 km and $g= 9.8 m/s^2$

Question

$$(a)\;1500 \;km \quad (b)\; 858\; km \quad (c)\;355\;km \quad (d)\;935\;km$$