document.write( "Question 56110: IF A ROCK IS DROPPED FROM A CLIFF INTO AN OCEAN, IT TRAVELS APPROXIMATELY 16t SQUARED FEET IN t SECONDS. IF THE SPLASH IS HEARD 4 SECONDS LATER AND THE SPEED OF SOUND IS 1,100 FT/SEC, APPROXIMATE THE HEIGHT OF THE CLIFF. \n" ); document.write( "
Algebra.Com's Answer #38083 by ankor@dixie-net.com(22740)\"\" \"About 
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\n" ); document.write( "We know that the distance the rock falls = distance the sound travels
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\n" ); document.write( "Let the time the rock fall = t; time the sound travels = (4-t)
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\n" ); document.write( "Rock dist = sound dist
\n" ); document.write( "16t^2 = 1100(4-t)
\n" ); document.write( "16t^2 = 4400 - 1100t
\n" ); document.write( "16t^2 + 1100t - 4400 = 0
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\n" ); document.write( "Simplify divide by 4
\n" ); document.write( "4t^2 + 275t - 1100 = 0
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\n" ); document.write( "Using the quadratic formula (and a good calculator) the positive solution:
\n" ); document.write( "t = 3.79096 seconds for the rock to fall
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\n" ); document.write( "Distance = 16 * 3.79096^2 = 229.94 ft
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\n" ); document.write( "Check the distance with the sound: 1100(4-3.79096) = 229.94 ft also
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