document.write( "Question 200633: If an object is projected upward with an initial velocity of 48 ft pe second from a height h of 160 ft, then its height t second after it is projected is defined by the equation h= -16t 2 + 48t + 160. How many seconds after it is projected will it hit the ground? \n" ); document.write( "
Algebra.Com's Answer #150887 by ankor@dixie-net.com(22740)\"\" \"About 
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If an object is projected upward with an initial velocity of 48 ft per second
\n" ); document.write( " from a height h of 160 ft, then its height t second after it is projected is
\n" ); document.write( " defined by the equation h= -16t 2 + 48t + 160.
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\n" ); document.write( " How many seconds after it is projected will it hit the ground?
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\n" ); document.write( "When the object strikes the ground h = 0, therefore:
\n" ); document.write( "-16t^2 + 48t + 160 = 0
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\n" ); document.write( "Simplify, divide by -16
\n" ); document.write( "t^2 - 3t - 10 = 0
\n" ); document.write( "Factor
\n" ); document.write( "(t - 5)(t + 2) = 0
\n" ); document.write( "Positive solution
\n" ); document.write( "t = 5 seconds to hit the ground
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\n" ); document.write( "Check solution in original equation
\n" ); document.write( "h = -16t^2 + 48t + 160
\n" ); document.write( "h = -16(5^2) + 48(5) + 160
\n" ); document.write( "h = -400 + 240 + 160
\n" ); document.write( "h = 0 \n" ); document.write( "
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