A NASA satellite has just observed an asteroid that is on a collision course with the Earth. The asteroid has?

A NASA satellite has just observed an asteroid that is on a collision course with the Earth. The asteroid has an estimated m, based on its size, of 5 � 109 kg. It is approaching the Earth on a head-on course with a velocity of 604 m/s relative to the Earth and is now 5.0 � 106 km away. With what speed will it hit the Earth's surface, neglecting friction with the atmosphere?