SOLUTION: a rocket is launched from the ground with an initial velocity of 48 feet per second, so that its distance in feet above the ground after t seconds is s(t)=-16t^2+48t. what is the m

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Question 1189385: a rocket is launched from the ground with an initial velocity of 48 feet per second, so that its distance in feet above the ground after t seconds is s(t)=-16t^2+48t. what is the maximum height of the rocket
Found 2 solutions by ikleyn, Alan3354:
Answer by ikleyn(52794) About Me  (Show Source):
You can put this solution on YOUR website!
.
a rocket is launched from the ground with an initial velocity of 48 feet per second,
so that its distance in feet above the ground after t seconds is s(t)=-16t^2+48t.
what is the maximum height of the rocket
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The function s(t) = -16t^2 + 48t  is a quadratic function, whose plot is a parabola opened down.


This quadratic function has the maximum at the value of its argument  t = -b%2F%282a%29, where 

"a" is the coefficient at  t^2  and "b" is the coefficient at t.


In your case, a= -16,  b= 48, so the function gets the maximum at  t = -48%2F%282%2A%28-16%29%29 = 1.5 seconds.


So, the ball gets the maximum height  1.5 seconds after is hit straight up. 


The maximum height is then  s(1.5) = - 16*1.5^2 + 48*1.5 = 36 feet.    ANSWER

Solved.

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To see many other similar solved problems,  slook 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
in this site.


On finding the maximum/minimum of a quadratic function,  learn from the lessons
    - HOW TO complete the square to find the minimum/maximum of a quadratic function
    - Briefly on finding the minimum/maximum of a quadratic function
    - HOW TO complete the square to find the vertex of a parabola
    - Briefly on finding the vertex of a parabola
in this site.



Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Not a rocket.
Rockets have thrust and accelerate upward.