Question

Select the correct answer. A model rocket was launched from the top of a building. The rocket's approximate height can be modeled by the quadratic equation h = -4.9t2 + 53.9t + 127.4, where h is the rocket's height, in meters, after t seconds. When factored, this equation is h = -4.9(t - 13)(t + 2). What is a reasonable time for it to take the rocket to land on the ground? Answer A 11 seconds Answer B 13 seconds Answer C 2 seconds Answer D 15 seconds

Answer 1

Answer:

13 seconds.

Step-by-step explanation:

Given

$h = -4.9(t - 13)(t + 2).$

Required

Determine a reasonable solution for t

To do this, we equate h to 0.

$h = -4.9(t - 13)(t + 2).$ becomes

$0 = -4.9(t - 13)(t + 2).$

Divide through by -4.9

$0 = (t - 13)(t + 2).$

Reorder the expression

$(t - 13)(t + 2) = 0.$

Split

$t-13 = 0$ or $t + 2 = 0$

This gives:

$t = 13$ or $t = -2$

But time can't be negative, So:

$t = 13$