document.write( "Question 372797: Jack wanted to throw an apple to Lauren, who was on a balcony 40 feet above him, so he tossed it upward with an initial speed of 56 ft/s. Lauren missed it on the way up, but then caught it on the way down. How long was the apple in the air?\r
\n" ); document.write( "\n" ); document.write( "Would I use the equation h(t) = -16t^2 + 56t +40? (where h = height and t = time) I'm not very good at solving quadratic word problems :( \n" ); document.write( "
Algebra.Com's Answer #265524 by nerdybill(7384)\"\" \"About 
You can put this solution on YOUR website!
Well, you're close
\n" ); document.write( "The general equation is
\n" ); document.write( "h(t) = -(1/2)gt^2 + Vot + h(0)
\n" ); document.write( "where
\n" ); document.write( "g is gravity 32 ft/sec^2
\n" ); document.write( "Vo is initial velocity
\n" ); document.write( "h(0) is initial height of Jack (not Lauren)
\n" ); document.write( ".
\n" ); document.write( "So, plugging in what we know
\n" ); document.write( "h(t) = -(1/2)(32)t^2 + 56t + 0
\n" ); document.write( "which reduces to
\n" ); document.write( "h(t) = -16t^2 + 56t
\n" ); document.write( ".
\n" ); document.write( "So, since Lauren is 40 feet up -- set h(t) to 40 and solve for t:
\n" ); document.write( "h(t) = -16t^2 + 56t
\n" ); document.write( "40 = -16t^2 + 56t
\n" ); document.write( "0 = -16t^2 + 56t - 40
\n" ); document.write( "multiply both sides by -1:
\n" ); document.write( "0 = 16t^2 - 56t + 40
\n" ); document.write( "divide both sides by 8:
\n" ); document.write( "0 = 2t^2 - 7t + 5
\n" ); document.write( "0 = (2t-5)(t-1)
\n" ); document.write( "So,
\n" ); document.write( "t = {1, 5/2}
\n" ); document.write( "1 sec represents the time the apple reaches 40 ft (going up)
\n" ); document.write( "So
\n" ); document.write( "5/2 secs or
\n" ); document.write( "2 and 1/2 secs (is your solution)\r
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