If a football player passes a football from 4 feet off the ground with an initial velocity of 36 feet per second, how long will it take the football to hit the ground? Use the equation h = -16t^2 + 36t + 4.

Question

vera_ewing · Answer

A. https://lss.brainhoney.com/Resource/22181721,AB4,0,B,0,0/Assets/71814_53b5a586/05_03c_5_01.gif B. https://lss.brainhoney.com/Resource/22181721,AB4,0,B,0,0/Assets/71814_53b5a586/05_03c_5_02.gif C. https://lss.brainhoney.com/Resource/22181721,AB4,0,B,0,0/Assets/71814_53b5a586/05_03c_5_03.gif D. https://lss.brainhoney.com/Resource/22181721,AB4,0,B,0,0/Assets/71814_53b5a586/05_03c_5_04.gif

vera_ewing · Answer

@dtan5457 This is the last one!

vera_ewing · Answer

@iambatman please please please help me? This is my last problem!

vera_ewing · Answer

I'm pretty sure it's A but idk....

anonymous · Answer

Can you show me your work?

anonymous · Answer

You just have to set it = 0 and solve

vera_ewing · Answer

Ugh it's on paper... will you wait for me to take a picture?

dtan5457 · Answer

Quadratic formula again..lol.

anonymous · Answer

Yes, take your time, and yes quadratic formula is good!

vera_ewing · Answer

@dtan5457 it's A right?

dtan5457 · Answer

-16t^2 + 36t + 4=0

i'd start by diving this by 4.

vera_ewing · Answer

-4t^2+9t+1=0/4

dtan5457 · Answer

no need to divide the 0

vera_ewing · Answer

oh ok now what?

dtan5457 · Answer

quadratic formula?

anonymous · Answer

Complete the square

anonymous · Answer

Yes, you can try using the quadratic formula as well

vera_ewing · Answer

t=[ − (−9)±√{(−9)²− 4×4×(− 1)}]/(2×4) 
=[ 9 ±√{81+ 16}]/(8) 
=[ 9±√{97}]/(8) 
=2. 356 Seconds

vera_ewing · Answer

but that's not one of my answer choices that's why i'm stuck :/

anonymous · Answer

You sure?

dtan5457 · Answer

you don't have to simplify to actual seconds here

anonymous · Answer

Check your options again.

dtan5457 · Answer

The answer is in there.

vera_ewing · Answer

Ohhhh wait hahaha

dtan5457 · Answer

once again you did the b^2-4ac wrong

dtan5457 · Answer

it's not a

vera_ewing · Answer

So is it C or D?

dtan5457 · Answer

D is not even in the correct form

vera_ewing · Answer

Oh ok. Thanks both of you @iambatman @dtan5457 :)

dtan5457 · Answer

No problem. any more questions?

vera_ewing · Answer

Nope that was the last one :) thank goodness lol

dtan5457 · Answer

;p

do things earlier next time :DD