일반물리학 1 — Motion in Two and Three Dimensions: Problem 39

39 In Fig. 4-28, a ball is thrown leftward from the left edge of the roof, at height $h$ above the ground. The ball hits the ground $1.50\text{ s}$ later, at distance $d = 25.0\text{ m}$ from the building and at angle $\theta = 60.0^\circ$ with the horizontal. (a) Find $h$. (Hint: One way is to reverse the motion, as if on video.) What are the (b) magnitude and (c) angle relative to the horizontal of the velocity at which the ball is thrown? (d) Is the angle above or below the horizontal?