Question

Fredrick threw a ball from the top of a building. The height of the ball, in feet, after it is thrown is modeled by the function

h() = -1612 + 641 + 100, where i represents time, in seconds.

Answer 1

5.2

Explanation:

Answer 2

• 5.2 seconds

Explanation:

Given

• The function h(t) = -16t^2 +64t + 100

To find:

• Time the ball to reach the ground (h = 0)?

Solution

• h(t) = -16t^2 +64t + 100

Need to find the value of t, when h(t) = 0

• -16t^2 +64t + 100 = 0
• 4t^2 - 16t - 25 = 0
• 4t^2 - 2*2t*4 + 16 = 41
• (2t - 4)^2 = 41
• 2t - 4 = √41
• 2t - 4 = 6.4
• 2t = 10.4
• t = 5.2

Answer is 5.2 seconds