A ball is thrown from the top row of seats in a stadium. The function h(t) = −16t2 + 64t + 80 gives the height, h, in feet, of the ball t seconds after it is thrown. How long will it be before the ball hits the ground?

Solving a quadratic equation, it is found that the ball hits the ground after 5 seconds.

The height of a ball after t seconds is given by:

It hits the ground at the values of t for which:

Then

Simplifying by -16:

Which is a quadratic equation with coefficients .

Then:

We want the positive value, thus, the ball hits the ground after 5 seconds.

A similar problem is given at link

Step-by-step explanation:

Given the height of the ball expressed as:

h(t) = −16t^2 + 64t + 80

The ball hits the ground the when h(t) = 0

Substitute h(t) = 0 and find t as shown:

h(t) = −16t^2 + 64t + 80

0 = −16t^2 + 64t + 80

−16t^2 + 64t + 80 = 0

Divide throigh by -16

t^2-4t-5 = 0

t^2-5t+t-5 = 0

t(t-5)+1(t-5) = 0

(t+1)(t-5)= 0

t+1 = 0 and t - 5 = 0

t = -1 and t = 5

time can not be negative:

t = 5seconds

Hence it will take 5 secs before the ball his the ground

fist on the left goes with the third on the right. second on the left goes with the fourth on the right. third on the left goes with the second on the right. the fourth on the left goes with first on the right

11

step-by-step explanation:

32.50-7.50=25

225/25=11