document.write( "Question 1042039: The height of a ball thrown upward from the top of a building is given by: h(t)=-16t^2+64t+80\r
\n" ); document.write( "\n" ); document.write( "What is the height of the ball at 1 second?\r
\n" ); document.write( "\n" ); document.write( "What is the maximum height reached by the ball? \r
\n" ); document.write( "\n" ); document.write( "How long will it take for the ball to reach the ground? \n" ); document.write( "
Algebra.Com's Answer #656944 by stanbon(75887)\"\" \"About 
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The height of a ball thrown upward from the top of a building is given by: h(t)=-16t^2+64t+80
\n" ); document.write( "What is the height of the ball at 1 second?
\n" ); document.write( "h(1) = -16+64+80 = 128 ft.
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\n" ); document.write( "What is the maximum height reached by the ball?
\n" ); document.write( "Max occurs when x = -b/(2a) = -64/(2*-16) = 2 sec
\n" ); document.write( "h(2) = -16(2^2) + 64(2) + 80 = 144 ft
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\n" ); document.write( "How long will it take for the ball to reach the ground?
\n" ); document.write( "When it reaches the ground the height is zero.
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\n" ); document.write( "Solve:: -16t^2+64t+80 = 0
\n" ); document.write( "t^2 - 4t - 5 = 0
\n" ); document.write( "(t-5)(t+1) = 0
\n" ); document.write( "Positive solution::
\n" ); document.write( "t = 5 seconds
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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