Question

A ball is launched into the sky at 19.5 feet per second from a 54.6 meter tall building. The equation for the ball’s height, h, at time t seconds is h = -3.9t^2 + 19.5t + 54.6. When will the ball strike the ground?

Answer 1

sorry dont know this answer to the question

Answer 2

Answer:

The ball strike the ground at time , t = 6 s

Step-by-step explanation:

Given:

The equation for the ball’s height, h, at time t seconds is

To Find:

time, t = ?   (When the ball strike the ground)

Solution:

When the ball strike the ground height, h will be ZERO,

So put h = 0 in above given equation for time,

Which is a Quadratic Equation

Dividing throughout by - 4.9 we get

On Factorizing, splitting the middle term we get

As time cannot be negative,

t = 6 s

Therefore,

The ball strike the ground at time , t = 6 s