A 64kg student is standing in the middle of a frozen pond with a frictionless surface while carrying 2 books, a physics book with a mass of 2.5kg and a biology textbook with a mass of 3.5kg. The physics book is thrown with a speed of 6m/s relative to the student to the right and then the biology book is thrown in the opposite direction with a speed of 4m/s relative to the student. Calculate the velocity of the student after the biology book is thrown.
Not entirely sure
E = 1/2mv(squared)??
The Attempt at a Solution
I dont have a clue how to start this question. Please any help would be greatly appreciated.