document.write( "Question 194403: A swimmer is about to dive into a pool from the end of a diving board that is 24 feet above the waters surface. if he springs up from the board at a speed of 8 feet per second, when will he hit the water? what will be his maximum height above the water? \n" ); document.write( "
Algebra.Com's Answer #145869 by Earlsdon(6294)\"\" \"About 
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You can use the equation for the height of an object propelled upwards from an initial height (\"h%5B0%5D\") with an initial velocity (\"v%5B0%5D\"):
\n" ); document.write( "\"h%28t%29+=+%281%2F2%29gt%5E2%2Bv%5B0%5Dt%2Bh%5B0%5D\" where g is the acceleration due to gravity, 32 ft/sec. sq. Making the appropriate substitutions:
\n" ); document.write( "\"h%28t%29+=+-16t%5E2%2B8t%2B24\"
\n" ); document.write( "To find the time the diver hits the water means to find the time (t) at which his height (h) is zero.
\n" ); document.write( "1) \"-16t%5E2%2B8t%2B24+=+0\" Factor out -8.
\n" ); document.write( "\"-8%282t%5E2-t-3%29+=+0\" Now factor the trinomial.
\n" ); document.write( "\"2t%5E2-t-3+=+%282t-3%29%28t%2B1%29\"=\"0\" So...
\n" ); document.write( "\"2t-3%29+=+0\" or \"t%2B1+=+0\" and...
\n" ); document.write( "\"t+=+3%2F2\" or \"t+=+-1\" Discard the negative solution as the time will be a positive value.
\n" ); document.write( "\"t+=+3%2F2\"
\n" ); document.write( "The diver will hit the water in 1.5 seconds.
\n" ); document.write( "His maximum height can be found by finding the coordinates of the vertex (a maximum) of the downward-opening parabola represented by the quadratic equation.
\n" ); document.write( "The t-value is given by:
\n" ); document.write( "\"t+=+-b%2F2a\" and a = -16, b = 8.
\n" ); document.write( "\"t+=+%28-8%29%2F2%28-16%29\"
\n" ); document.write( "\"t+=+1%2F4\"seconds. Now substitute this value of t into equation 1) above and solve for h.
\n" ); document.write( "\"h%281%2F4%29+=+-16%281%2F4%29%5E2%2B8%281%2F4%29%2B24\"
\n" ); document.write( "\"h%281%2F4%29+=+-16%281%2F16%29%2B%288%2F4%29%2B24\"
\n" ); document.write( "\"h%281%2F4%29+=+-1%2B2%2B24\"
\n" ); document.write( "\"h%281%2F4%29+=+25\"feet.
\n" ); document.write( "The diver attains a maximum height of 25 feet above the water.
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