document.write( "Question 966874: An object is launched straight up into the air. Its height in feet, or h, after t seconds is given by the equation h = –16t2 + 48t + 10. \r
\n" ); document.write( "\n" ); document.write( "1. Determine how much time has elapsed when the object is 30 feet above the ground. \r
\n" ); document.write( "\n" ); document.write( "2. Determine the projectile’s distance from the ground at the instant that the projectile is fired. \n" ); document.write( "
Algebra.Com's Answer #590922 by lwsshak3(11628)\"\" \"About 
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An object is launched straight up into the air. Its height in feet, or h, after t seconds is given by the equation h = –16t2 + 48t + 10.
\n" ); document.write( "1. Determine how much time has elapsed when the object is 30 feet above the ground.
\n" ); document.write( "30=-16t^2+48t+10
\n" ); document.write( "0=-16t^2+48t-20
\n" ); document.write( "4t^2-12t+5=0
\n" ); document.write( "(2t-5)(2t-1)=0
\n" ); document.write( "t=5/2=2.5
\n" ); document.write( "or
\n" ); document.write( "t=1/2
\n" ); document.write( "the object is 30 feet above the ground 1/2 sec after launch on the way up and 2.5 sec after launch on the way down.
\n" ); document.write( "..
\n" ); document.write( "2. Determine the projectile’s distance from the ground at the instant that the projectile is fired.
\n" ); document.write( "h = –16t2 + 48t + 10
\n" ); document.write( "at the instant that the projectile is fired, t=0, so h=10=the projectile’s distance from the ground \n" ); document.write( "
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