Final answer:
To find the height from which a ball is thrown horizontally, calculate the time the ball is in the air using horizontal motion, then apply that time to the vertical motion equation to find the height.
Step-by-step explanation:
The question deals with projectile motion and requires applying the principles of physics to find the height from which a ball thrown horizontally hits the ground. Given the initial horizontal velocity (vi) of 28.0 m/s and the horizontal distance (d) traveled is 50.0 m, we can calculate the time (t) it was in the air using the formula d = vit. Once t is determined, we use the vertical motion equation (h = 1/2gt2) to find the height it was thrown from, where g is the acceleration due to gravity (9.81 m/s2).