Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #7:

A 30 kg ball is launched at an angle of 15 degrees and is moving 20 m/s when it hits the ground. How fast would it be moving when it hits the ground if it were launched at an angle of 35 degrees if we ignore air resistance? Why? (20 m/s)