document.write( "Question 407696: lauren dove into a swimming pool from 15 foot high diving board with an initial velocity of 8 per second. Find the time t in seconds it took lauren to enter the water. Use the model for velocity motion given by the equation h=16t^2+vt+s, where h is height in feet , t is seconds, v is the initial upward velocity in feet per second, and s is the initial height in feet. \n" ); document.write( "
Algebra.Com's Answer #287430 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
lauren dove into a swimming pool from 15 foot high diving board with an initial velocity of 8 per second.
\n" ); document.write( " Find the time t in seconds it took lauren to enter the water.
\n" ); document.write( " Use the model for velocity motion given by the equation h=16t^2+vt+s, where
\n" ); document.write( " h is height in feet , t is seconds, v is the initial upward velocity in feet
\n" ); document.write( " per second, and s is the initial height in feet.
\n" ); document.write( ":
\n" ); document.write( "I think the equation should be h = -16t^2 + vt + s (-16t^2 is the downward force of gravity)
\n" ); document.write( ":
\n" ); document.write( "When the diver strikes the water, h = 0, therefore
\n" ); document.write( "-16t^2 + 8t + 15 = 0
\n" ); document.write( "Multiply by -1 and try to factor this
\n" ); document.write( "16t^2 - 8t - 15 = 0
\n" ); document.write( "(4t - 5)(4t + 3) = 0
\n" ); document.write( "Positive solution
\n" ); document.write( "4t = 5
\n" ); document.write( "t = \"5%2F4\"
\n" ); document.write( "t = 1.25 seconds to hit the water
\n" ); document.write( ":
\n" ); document.write( "Graphically:
\n" ); document.write( "\"+graph%28+300%2C+200%2C+-1%2C+2%2C+-5%2C+22%2C+-16x%5E2%2B8x%2B15%29+\" \n" ); document.write( "
\n" );