Question

A 0.01-kg baseball traveling in a horizontal direction with a speed of 11 m/s hits a bat and is popped straight up with a speed of 15 m/s.
(a) What is the change in momentum (magnitude and direction) of the baseball?

Answer 1

They already told you that the direction change is 90 degrees, from horizontal to "up". Use the Pythagorean Theorem for the magnitude.