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anonymous
 one year ago
NEED HELP ASAP. WILL FAN AND MEDAL.
A firecracker shoots up from a hill 150 feet high, with an initial speed of 110 feet per second. Using the formula H(t) = 16t^2 + vt + s, approximately how long will it take the firecracker to hit the ground?
Eight seconds
Nine seconds
10 seconds
11 seconds
anonymous
 one year ago
NEED HELP ASAP. WILL FAN AND MEDAL. A firecracker shoots up from a hill 150 feet high, with an initial speed of 110 feet per second. Using the formula H(t) = 16t^2 + vt + s, approximately how long will it take the firecracker to hit the ground? Eight seconds Nine seconds 10 seconds 11 seconds

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@pooja195 @Concentrationalizing

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0If the hill is 150 feet high, then that's essentially saying that when t = 0, h(t) should equal 150. An initial speed of 110 feet just tells you that v = 110. Using that information, you can rewrite h(t) as a quadratic in t only in which then you would just factor and solve for t.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ok, can you walk me through it? :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Well, if you plug in t = 0, what do you get?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Well, if t is 0, the 16 goes away also. \(16(0)^{2} +v(0) + s = s\) . In the end, the problem just tells you that s = 150 and v = 110.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Well, that means you have \(h(t) = 16t^{2} +110t + 150\) So, h(t) represents height. You plug in a time value and you get a height for an answer. The problem wants to know when you hit the ground. Well, if you hit the ground, then the height is 0. So we want to know what time value will make h(t) equal 0. Following me so far?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oh ok :D I think so.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Mhm. So if h(t) needs to be 0, then you're solving this: \(16t^{2} + 110t + 150 = 0\)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ok just give me a minute...

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ok, I think I got lost. I only got to the beginning: 16t^2 + 110t = 150. :(

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0After that I don't know what to do.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Well, this is a quadratic equation, so it needs to be factored.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ok, so 2t(8t  55) = 150?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Nope. Have you seen before how an equation like \(x^{2} + 5x + 6\) turns into \((x+2)(x+3)\)?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yes, I have. :) So I need to do that here?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yeah, its that idea. So itll factor and look like ( )( ) = 0 Now it's just knowing how to factor in that way.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Hmm. So would it start to look like (4t +/ ___)(4t +/ ___)?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Actually, this doesnt factor cleanly. Since the question said "approximately", we won't be able to factor in the way I was thinking. We're actually forced to quadratic formula on this, I apologize.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oh ok! That's fine :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Youre okay with doing quadratic formula correctly? :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yes. Here give me just a few minutes ;) things around here are getting a bit crazy XD

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ok so is it 8.04 or 1.17?? Oh so then it would be eight seconds??

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Sorry I took so long lol

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I didnt do the full math, but itd be 8 seconds, yeah :3

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ok thanks! I'll give you a medal but I'm already a fan ;)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Lol, okay. As long as it makes sense.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yes it does now ;) because of you. Thanks so much! Ttyl :)
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