SOLUTION: This is the exact equation she gave me: "A child tosses a ball upward with an initial velocity of 10 f/s at a height of 3 feet. If it is not caught, how long will it be in the air?

Question 299546: This is the exact equation she gave me: "A child tosses a ball upward with an initial velocity of 10 f/s at a height of 3 feet. If it is not caught, how long will it be in the air?"
The formula she gave us to use is h(t)=-16^2+vt+s
I tried setting it equal to zero but got lost after that.
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
This is the exact equation she gave me: "A child tosses a ball upward with an initial velocity of 10 f/s at a height of 3 feet. If it is not caught, how long will it be in the air?"
The formula she gave us to use is h(t)=-16^2+vt+s
I tried setting it equal to zero but got lost after that.
---------------
If you set it to zero, you can find the time when it hits the ground, when h=0. That's how long it is in the air.
h(t)=-16^2+vt+s
Actually, it's h(t)=-16t^2+vt+s
h(t) = -16t^2 + 10t + 3
-16t^2 + 10t + 3 = 0

Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)

Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=292 is greater than zero. That means that there are two solutions: .

Quadratic expression can be factored:

Again, the answer is: -0.221500234082346, 0.846500234082346. Here's your graph:

---------------
Ignore the negative number.
t =~0.8465 seconds to impact
You were doing it right, setting it to zero.

RELATED QUESTIONS
I would like to know if you would be able to help me with this problem. using this... (answered by jim_thompson5910)

Suppose a child throws a ball upward and gives it an initial velocity of 10 feet per... (answered by ankor@dixie-net.com)

Could someone help me please? The problem is: A ball is thrown upward from the roof of a (answered by Flake,Earlsdon)

A ball is thrown upward from the roof of a building 100 m tall with an initial velocity... (answered by Edwin McCravy)

A ball is thrown upward from the roof of a building 100 m tall with an initial velocity... (answered by Nate)

I don't know how to find or write the equation on this question that says zen throws a... (answered by ikleyn)

Solving a science application. Suppose that a ball is thrown upward with an initial... (answered by jim_thompson5910)

The constant is always equal to the initial height of the ball (80 m in our previous... (answered by renevencer22)

A ball is thrown upward into the air with an initial velocity of 128ft/s. The equation... (answered by Earlsdon)