SOLUTION: A model rocket is launched with an initial an initial upward velocity of 50 m/s. The rockets height “h” (in meters) after “t” seconds is given by the following. H=50t-5t

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Question 1145783: A model rocket is launched with an initial an initial upward velocity of 50 m/s. The rockets height “h” (in meters) after “t” seconds is given by the following.
H=50t-5t squared
Find all values of “t” for which the rockets height is 20 meters
Round your answer to the nearest hundredth
This was my answer? I just want to make sure it’s right!
Answer:3.25, 3.94
Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
A model rocket is launched with an initial an initial upward velocity of 50 m/s. The rockets height “h” (in meters) after “t” seconds is given by the following.
H=50t-5t squared
Find all values of “t” for which the rockets height is 20 meters
-------
H=50t-5t^2 = 20
t^2 - 10t + 4 = 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=84 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: 9.58257569495584, 0.41742430504416. Here's your graph:

==================
This is more descriptive:
-5t^2 + 50t - 20 = 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=2100 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: 0.41742430504416, 9.58257569495584. Here's your graph:

=========================================================
Round your answer to the nearest hundredth
This was my answer? I just want to make sure it’s right!
Answer:3.25, 3.94
-------------------
It might be instructive to see how you got your answers.
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