document.write( "Question 886833: Part of a cheerleading routine is throwing a flyer straight up and catching her on the way down. The flyer begins this move with her center of gravity 4 feet above the ground. She is thrown with an initial vertical velocity of 30 feet per second.
\n" ); document.write( "So knowing this:
\n" ); document.write( " Will the flyer’s center of gravity ever reach 20 feet?
\n" ); document.write( " For the flyer to have her center of gravity reach 25 feet, what does the initial velocity need to be? Thanks. \n" ); document.write( "
Algebra.Com's Answer #536179 by rothauserc(4718)\"\" \"About 
You can put this solution on YOUR website!
h(t) = -16t^2 +(vo)(t) + ho, where vo=velocity in ft/sec and ho= initial height in ft
\n" ); document.write( "we are given vo = 30 and ho = 4, therefore
\n" ); document.write( "h(t) = -16t^2 +30t +4
\n" ); document.write( "now we know that the x coordinate of the max altitude is -b/2a and in our problem
\n" ); document.write( "t = -b/2a = -30/(2*-16) = 0.9375
\n" ); document.write( "so max height is reached in 0.9375 seconds, now we can calculate the max height
\n" ); document.write( "h(0.9375) = -16*(0.9375^2) +30*0.9375 +4
\n" ); document.write( "h(0.9375) = 18.0625 feet
\n" ); document.write( "The flyer's center of gravity does not reach 20 feet
\n" ); document.write( "now find initial velocity to reach 25 feet
\n" ); document.write( "25 = -16*(0.9375^2) +vo*0.9375 +4
\n" ); document.write( "25 = −14.0625 +vo*0.9375 +4
\n" ); document.write( "vo*0.9375 = 35.0625
\n" ); document.write( "vo = 37.4 feet per second
\n" ); document.write( "therefore the initial velocity must be 37.4 feet per second to reach a height of 25 feet\r
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