document.write( "Question 625414: if an M-16 is fired straight upward, then the height h(t) of the bullet in feet at time t in seconds is given by h(t) = -16t^2 + 325t\r
\n" ); document.write( "\n" ); document.write( "a. what is the height of the bullet 5 seconds after it is fired ? evaluate h(5)
\n" ); document.write( "b. How long does it take for the bullet to return to earth ? \n" ); document.write( "
Algebra.Com's Answer #393526 by lwsshak3(11628)\"\" \"About 
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if an M-16 is fired straight upward, then the height h(t) of the bullet in feet at time t in seconds is given by h(t) = -16t^2 + 325t
\n" ); document.write( "a. what is the height of the bullet 5 seconds after it is fired ? evaluate h(5)
\n" ); document.write( "h(5) = -16*5^2 + 325*5
\n" ); document.write( "h(5) = -400 + 325*5
\n" ); document.write( "h(5) = 1225 ft (height of bullet 5 sec after it is fired)
\n" ); document.write( "..
\n" ); document.write( "b. How long does it take for the bullet to return to earth ?
\n" ); document.write( "When bullet returns to earth, h(5)=0
\n" ); document.write( "0 = -16t^2 + 325t
\n" ); document.write( "-16t^2 + 325t=0
\n" ); document.write( "-t(16t-325)=0
\n" ); document.write( "t=0 (reject, t>0)
\n" ); document.write( "or
\n" ); document.write( "16t-325=0
\n" ); document.write( "t=325/16
\n" ); document.write( "t≈20.31 sec (How long it takes for bullet to return to earth)
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