SOLUTION: An object is launched into the air from a ledge 6 feet off the ground at initial vertical velocity of 96 feet per second. Its height H, in feet, at t second is given by the equatio

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: An object is launched into the air from a ledge 6 feet off the ground at initial vertical velocity of 96 feet per second. Its height H, in feet, at t second is given by the equatio      Log On


   

Question 1087720: An object is launched into the air from a ledge 6 feet off the ground at initial vertical velocity of 96 feet per second. Its height H, in feet, at t second is given by the equation H = 16t^2+96t+16. Find all the times t that the object is at a height of 160 feet off the ground.
Found 2 solutions by ikleyn, josmiceli:
Answer by ikleyn(52778) About Me  (Show Source):
You can put this solution on YOUR website!
.
I just answered to this post at
https://www.algebra.com/algebra/homework/quadratic/Quadratic_Equations.faq.question.1087634.html

https://www.algebra.com/algebra/homework/quadratic/Quadratic_Equations.faq.question.1087634.html

saying that your post contains at least TWO errors (one of which is FATAL).


I asked you to double check your input and to fix the errors.


In response, you did NOTHING, submitting the post with no change and with the same errors.

So, AGAIN:

Carefully check your post.

Read and re-read it until you find the errors.

Then fix them.

Then re-post.



Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The equation should be:
+H+=+-16t%5E2+%2B+96t+%2B+6+
( I noted you said at +t=0+ the
object was +6+ ft off the ground,
it should be +16+ ft. )
----------------------------------
+H+=+-16t%5E2+%2B+96t+%2B+16+
+H+=+160+
+160+=+-16t%5E2+%2B+96t+%2B+16+
+-16t%5E2+%2B+96t+-+144+
+-t%5E2+%2B+6t+-+9+=+0+
+%28+t+-+3+%29%2A%28+-t+%2B+3+%29+=+0+
+t+=+3+
The object is at a height of 160 ft
only once, at t = 3 sec
--------------------------------
check:
here's the plot:
+graph%28+400%2C+400%2C+-1%2C+7%2C+-18%2C+180%2C+-16x%5E2+%2B+96x+%2B+16+%29+
My answer looks about right