SOLUTION: If a skydiver jumps from an airplane at a height of 8256 feet, then for the first 5 seconds, her height above the earth is approximated by the formula: h=-t^2+8256 . How many sec

Question 141175: If a skydiver jumps from an airplane at a height of 8256 feet, then for the first 5 seconds, her height above the earth is approximated by the formula: h=-t^2+8256 . How many seconds does it take her to reach 8000 feet?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
If a skydiver jumps from an airplane at a height of 8256 feet, then for the first 5 seconds, her height above the earth is approximated by the formula: h=-t^2+8256 . How many seconds does it take her to reach 8000 feet?
0 solutions
-------------------
h(t) = -t^2+8256
-t^2 + 8256 = 8000
-t^2 = -256
t = sqrt(256) = 16 seconds
--------------
Cheers,
Stan H.
RELATED QUESTIONS
Thank you for your help on this one skydiving If a skydiver jumps from an airplane at a (answered by stanbon)

#68 I have tried to work this problem but I am having much trouble can you help, please.... (answered by stanbon)

I have this problem that I would like someone to check my work: If a skydiver jumps... (answered by venugopalramana)

If a skydiver jumps from a airplane at a height of 8,256 ft, then for the first 5... (answered by Earlsdon)

An airplane is flying at an altitude of 1000 meters. A skydiver jumps from the plane with (answered by Boreal)

Please Help! # 81 Skydiving. If there were no air resistance, then the height (in feet)... (answered by stanbon)

Skydiving. If there were no air resistance, then the height (in feet) above the earth for (answered by stanbon,rajagopalan)

#67. I am not sure how to proceed can you help? Skydiving. If there were no air... (answered by stanbon)

A skydiver jumps from an altitude of 4000 m. Her height above the ground in metres after... (answered by addingup,ikleyn)