Question

A ball falls from a window. It's height, as a function of time, is modleled by y= -4.9x2 +12. Which statement best describes the function? A. Not enough information is given to decide.

Answer 1

Explanation:

Given the the height covered by the ball modeled by the equation

y= -4.9x²+12

Since we are not told what to find, we can as well find the time taken by the ball to reach the ground.

The ball hits the ground when y = 0. Substitute y = 0 into the equation and calculate x;

y= -4.9x²+12

0 = -4.9x²+12

Subtract 12 from both sides

0-12 = -4.9x²+12-12

-12 = 4.9x²

x² = -12/4.9

x² = 2.448

x = √2.448

x = 1.57s

Hence we can say that the ball hits the ground after 1.57s.