# algebra

posted by .

You throw a tennis ball up in the air from an initial height of 4 feet and an initial velocity of 36 feet per
second. Will the ball reach a height of 30 feet? If so, how long will it take?

• algebra -

you should know that
height = -16t^2 + 36t + 4

so 30 = -16t^2 + 36t + 4
16t^2 - 36t + 26 = 0
8t^2 - 18t + 13 = 0
use the quadratic equation to solve for t
( you should get an imaginary root, so the ball never reaches a height of 30 feet)

## Similar Questions

1. ### Algebra

THe function h(t)=-16t^2+v0t+h0 describes the height in feet above the ground h(t) of an object thrown vertically from a height of h0 feet, with an initial velocity of v0 feet per second, if there is no air friction and t is the time …
2. ### Algebra

THe function h(t)=-16t^2+v0t+h0 describes the height in feet above the ground h(t) of an object thrown vertically from a height of h0 feet, with an initial velocity of v0 feet per second, if there is no air friction and t is the time …
3. ### math

Let’s suppose you throw a ball straight up with an initial speed of 50 feet per second from a height of 6 feet. a.Find the parametric equations that describe the motion of the ball as a function of time. b.How long is the ball in …
4. ### algebra

Patty is only 7 years old, but she insists she can play basketball with a regulation-height hoop. She can throw the ball with an initial velocity of 11 feet per second. The equation for the height of the ball is y = −16t2 + vt …
5. ### algebra

Patty is only 7 years old, but she insists she can play basketball with a regulation-height hoop. She can throw the ball with an initial velocity of 11 feet per second. The equation for the height of the ball is y = −16t2 + vt …
6. ### algebra (parabolas)

you throw a wad of used paper towards a wastebasket from a height of about 1.3 feet above the floor with an initial vertical velocity of 3 feet per second. a. write and graph a function that models the height h (in feet) of the paper …
7. ### math

a baseball is hit with an initial velocity of 75 feet per second from the height of 3 feet. The function h(t)=-16t squared + 75t + 3 models the path of the baseball where t represents the time in seconds that the ball has been traveling …
8. ### Math

You throw a ball into the air with an initial vertical velocity of 31 feet per second. The ball leaves your hand when it is 6 feet above the ground. You catch the ball when it reaches a height of 4 feet. After how many seconds do you …
9. ### Algebra

The height of a ball thrown directly up with a velocity of 40 feet per second from a initial height of of 5 feet is given by the equation h(t)=-16t^2+40t+5, where t is the time in seconds and h is the ball’s height, measured in feet. …
10. ### algebra 2

A ball is thrown directly upward from an initial height of 200 feet with an initial velocity of 96 feet per second. After t seconds, the height of the ball above the ground is s(t) = 16t2+ 96t + 200. a. After how many seconds …

More Similar Questions