Question

1. A ball is thrown into the air. The height in feet of the ball can be modeled by the equation h = -16t2 + 20t + 6 where t is the time in seconds, the ball is in the air. When will the ball hit the ground? How high will the ball go?

Help please and show all work.

Answer 1

im thinking the ball will hit the ground in 8 seconds. times that and u get 16. im sorry if im wrong
 

Answer 2

You want to know the times when h = 0

So set the equation equal to 0

0 = -16t^2 + 20t + 6
16t^2 - 20t - 6 = 0
2(8t^2 - 10t - 3) = 0
2(4t + 1)(t - 3) = 0
set each factor equal to 0
4t + 1 = 0                       t - 3 = 0
4t = -1                            t = 3 - how long when the ball hits the ground
t = -1/4 (not valid can't have negative time)