### Home > PC3 > Chapter 13 > Lesson 13.2.2 > Problem 13-79

13-79.

A ball is thrown off of a roof with a velocity of

Write a set of parametric equations to model the position of the ball in relationship to its starting position at any time

seconds after it was thrown.An object that is launched with an initial position of

and an initial velocity of and an angle of will travel along a path defined by the parametric function: where

and are measured in feet and is measured in seconds. How far does the ball travel horizontally before it hits the ground?

The ball hits the ground when

. Solve that equation first.

Then computeusing the time at which the ball hit the ground.