Question: A science student is riding on a flatcar of a train travelling along a straight horizontal track at a constant speed of 10.0 m/s. The student throws a ball into the air along a path that he judges to be to make an initial angle of 60.0° with the horizontal and to be in line with the track. The student's professor, who is standing on the ground nearby, observes the ball to rise vertically.

Part A: How high does she see the ball rise?

Thanks in advance that solve the above question.