A projectile is launched at some angle to the horizontal with some initial speed vi, and air resistance is negligible. (a) Is the projectile a freely falling body? Yes (b) What is its acceleration in the vertical direction? (Let up be the positive direction.) m/s" (c) What is its acceleration in the horizontal direction? 0 m/s" Use the worked example above to help you solve this problem. A ball is thrown upward from the top of a building at an angle of 30.0" to the horizontal and with an initial speed of 23.0 m/s. The point of release is h = 48.0 m above the ground. (a) How long does it take for the ball to hit the ground? s (b) Find the ball's speed at impact. m/s (c) Find the horizontal range of the ball. m EXERCISE Suppose the ball is thrown from the same height as in the PRACTICE IT problem at an angle of 32.0" below the horizontal. If it strikes the ground 48.2 m away, find the following. (Hint: For part (a), use the equation for the x-displacement to eliminate v0t from the equation for the y-displacement.) (a) the time of flight s (b) the initial speed m/s (c) the speed and angle of the velocity vector with respect to the horizontal at impact speed m/s angle below the horizontal