2 kg projectile flying at a speed of 300 m / s, misses the target weight of sand and 100kg stuck therein. How fast and in what direction will move to the target after being hit by a projectile, if the target is moving at a meeting with the projectile speed of 72 km / h?

Detailed solution shorthand terms, formulas and laws used in the decision, the withdrawal of the calculation formula and the response.
If you have any questions to address, please. I try to help.