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- 1. Please explain 14. A boy throws a ball from the ground to the top of a building. The ball just lands on the edge of the top of the building. (4 pts) Which of the trajectories shown on the drawing would the ball follow to the top of the building? a) + X b) (4 pts). The ball is in flight for 1.5 seconds. Just as the boy releases the ball, what is the y component of the initial velocity of the ball? At the instant the boy releases the ball, how does the speed of the ball compare to the y component of the initial velocity of the ball? just in words -no calculation necessary) c) (2 pts) Solution (A) the ball will follow the path ( c) (b) along vertical initial velocity = voy at teh top final velocity vy = 0 acceleration ay = -g = -9.8 m/s^2 tiem taken t = 1.5 s
- 2. vy = voy + ay*t 0 = voy - 9.8*1.5 voy = 14.7 m/s = 15 m/s ====================== c) the speed of the ball = vo vertical component = voy = vo*sintheta voy , vo the speed vo of the ball is always greater than the y component