For a Science Olympiad competition, a group of middle school students build a trebuchet that can fire

Question:

For a Science Olympiad competition, a group of middle school students build a trebuchet that can fire a tennis ball from a height of 1.55 m with a velocity of 10.5 m/s and a launch angle of 35.0° above the horizontal. What is the x-component of the velocity of the tennis ball just before it hits the ground?