Need help
Mark is in a deep hole looking for treasure. He is standing 8 feet below the surface. He throws an old coin he found with an initial upward velocity of 22 ft/sec. How long until it lands outside the hole, having gone up and come back down? Use the formula h=-16t^2+22t-8, where h is the height of the coin in feet (relative to the surface) and t is the time in seconds since Mark threw it. Ignore air resistance and round your answer to the nearest tenth.

A.
0.3 seconds
B.
1.7 seconds
C.
2.1 seconds
D.
It will not make it outside the hole.

Question

Need help
Mark is in a deep hole looking for treasure. He is standing 8 feet below the surface. He throws an old coin he found with an initial upward velocity of 22 ft/sec. How long until it lands outside the hole, having gone up and come back down? Use the formula h=-16t^2+22t-8, where h is the height of the coin in feet (relative to the surface) and t is the time in seconds since Mark threw it. Ignore air resistance and round your answer to the nearest tenth.

A.
0.3 seconds
B.
1.7 seconds
C.
2.1 seconds
D.
It will not make it outside the hole.

misssunshinexxoxo · Answer

What do you believe the answer is?

anonymous · Answer

IT has to be D i've been stuck in this question for a while

misssunshinexxoxo · Answer

Sounds like physics I'll help you

misssunshinexxoxo · Answer

h = -16t^2+22t-8 
h' = -32t + 22 = 0 
t = 11/16 
h = -16 (11/16)^2 +22(11/16) - 8 
h = -0.4375 it will not make it out of the hole.

misssunshinexxoxo · Answer

Yes you are correct! :) Way to go

anonymous · Answer

Thanks