Question

An object is dropped from a small plane. As the object falls, its distance, d, above the ground after t seconds, is given by the formula d = –16t2 + 1,000. Which inequality can be used to find the interval of time taken by the object to reach the height greater than 300 feet above the ground?

Answer 1

Answer:

$-16t^2 + 1000>300$

$t\in (9.01,\infty)$

Step-by-step explanation:

We are given the following in the question:

$d = -16t^2 + 1000$

where d is the distance of an object above the ground and t is in seconds.

We have to find the time interval such that distance is greater than 300 feet above the ground.

$d > 300\\d = -16t^2 + 1000>300\\-16t^2>-1300\\t^2 > 81.25\\t > \sqrt{81.25}\\t > 9.013\\\Rightarrow t\in (9.01,\infty)$

is the required time interval.