SOLUTION: A rocket is shot into the air and travels h = −4.9t^2 +30t + 45 where h is the height of the object and t is in seconds. What is the time when the object hits the ground to the n

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: A rocket is shot into the air and travels h = −4.9t^2 +30t + 45 where h is the height of the object and t is in seconds. What is the time when the object hits the ground to the n      Log On


   

Question 1137871: A rocket is shot into the air and travels h = −4.9t^2 +30t + 45 where h is the height of the object and t is in seconds. What is the time when the object hits the ground to the nearest tenth of a second?
Found 2 solutions by ikleyn, Alan3354:
Answer by ikleyn(52777) About Me  (Show Source):
You can put this solution on YOUR website!
.
It will happen when h(t) = 0.


To determine this time moment, you need to solve this quadratic equation


    -4.9t^2 + 30t + 45 = 0.


I will leave the solution to you.

If you want to see many similar solved problems and to have them as your templates,  look into the lessons

    - Problem on a projectile moving vertically up and down
    - Problem on an arrow shot vertically upward
    - Problem on a ball thrown vertically up from the top of a tower
    - Problem on a toy rocket launched vertically up from a tall platform

Consider these lessons as your textbook,  handbook,  tutorials and  (free of charge)  home teacher.
Read them attentively and learn how to solve this type of problems once and for all.

Also,  you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic "Projectiles launched/thrown and moving vertically up and dawn".


Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.


Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
That is not a rocket.
It's a projectile.
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Rocket launches, by NASA and others, are sometimes televised.
They don't just fall back to Earth.