Question

Sharon kicks a ball from the ground into the air with an upward velocity of 64 feet per second. The function h = -16t2 + 64t models the height h, in feet, of the ball at time t, in seconds. When will the ball reach the ground again? 1 second after the ball is thrown 2 seconds after the ball is thrown 3 seconds after the ball is thrown 4 seconds after the ball is thrown

Answer 1

4 seconds ................

Answer 2

To find when the ball reaches the ground, you would need to find the time that gives you a height value of zero. 

Your answer would be 4 seconds

h = -16(4)^2 + 64(16)
h = -16(16) + 256
h = -256 + 256
h = 0

Hope this helps!