일반물리학 1 — Motion in Two and Three Dimensions: Problem 48

48 In Fig. 4-32, a ball is thrown up onto a roof, landing 4.50 s later at height h = 20.0 m above the release level. The ball's path just before landing is angled at \(\theta = 60.0^\circ\) with the roof. (a) Find the horizontal distance d it travels. (See the hint to Problem 39.) What are the (b) magnitude and (c) angle (relative to the horizontal) of the ball's initial velocity?