An asteroid is moving directly towards the centre of the earth. When at a distance of 10 R (R is the radius of the earth) from the earths centre, it…

An asteroid is moving directly towards the centre of the earth. When at a distance of $\displaystyle 10$ R (R is the radius of the earth) from the earths centre, it has a speed of $\displaystyle 12$ km/s. Neglecting the effect of earths atmosphere, what will be the speed of the asteroid when it hits the surface of the earth (escape velocity from the earth is $\displaystyle 11.2 \mathrm{~km} / \mathrm{s}$ )? Give your answer to the nearest integer in kilometer/s \_\_\_\_.