Chapter 6.2, Problem 75E

Projectile Motion In Exercises 75 and 76, consider the path of an object projected horizontally with a velocity of $v$ feet per second at a height of $s$ feet, where the model for the path is

$x^2=-\frac{v^2}{16}\left(y-s\right)$.

In this model (in which air resistance is disregarded), $y$ is the height (in feet) of the projectile and $x$ is the horizontal distance (in feet) the projectile travels.

A ball is thrown from the top of a 100-foot tower with a velocity of 28 feet per second.

(a) Write an equation for the parabolic path.

(b) How far does the ball travel horizontally before it strikes the ground?