SOLUTION: When a ball is thrown, its height in feet "h" after "t" seconds is given by the equation h = vt - 16t^2 In this equation, v is the initial upwards velocity in feet per second.

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Question 39028: When a ball is thrown, its height in feet "h" after "t" seconds is given by the equation
h = vt - 16t^2
In this equation, v is the initial upwards velocity in feet per second. If v = 28 feet per second, find all values of t for which h = 12 feet.
Found 2 solutions by stanbon, checkley71:
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
h = vt - 16t^2
In this equation, v is the initial upwards velocity in feet per second. If v = 28 feet per second, find all values of t for which h = 12 feet.
h=28t-16t^2
12=28t-16t^2
-16t^2+28t-12=0

Solved by pluggable solver: SOLVE quadratic equation with variable

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=16 is greater than zero. That means that there are two solutions: .

Quadratic expression can be factored:

Again, the answer is: 0.75, 1. Here's your graph:

Hope this helps.
Cheers,
Stan H.

Answer by checkley71(8403) (Show Source):
You can put this solution on YOUR website!
12=24T-16t~2 or 16t~2-24t+12=0 or 4t~2-7t+3=o or (4t-3)(t-1)=0 or 4t-3=0 or
t=3/4 & t=1