document.write( "Question 1155163: Solve step by step. \r
\n" ); document.write( "\n" ); document.write( "18. A tennis ball is launched straight upward with an initial velocity of 24.5 m/s from the edge of a cliff that is 117.6 meters above the ground. Which quadratic equation could be used to correctly determine when the ball will hit the ground:\r
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\n" ); document.write( "\n" ); document.write( "4.9t^2 + 24.5t + 117.6 = 0\r
\n" ); document.write( "\n" ); document.write( "-4.9t^2 - 24.5t + 117.6 = 0\r
\n" ); document.write( "\n" ); document.write( "-4.9t^2 + 24.5t - 117.6 = 0\r
\n" ); document.write( "\n" ); document.write( "4.9t^2 + 24.5t - 117.6 = 0\r
\n" ); document.write( "\n" ); document.write( "-4.9t^2 + 24.5t + 117.6 = 0\r
\n" ); document.write( "\n" ); document.write( "19. Solve the equation you chose in question 18 to determine when the ball will hit the ground. (HINT: If you don't get one of the answers listed for this question, then maybe you chose the wrong equation in #18. Use this opportunity to double check your work!)
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\n" ); document.write( "t = 8 seconds\r
\n" ); document.write( "\n" ); document.write( "t = 4 seconds\r
\n" ); document.write( "\n" ); document.write( "t = 3 seconds\r
\n" ); document.write( "\n" ); document.write( "t = -3 seconds\r
\n" ); document.write( "\n" ); document.write( "The ball will never reach the ground.\r
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\n" ); document.write( "20. Using the same equation, determine when the ball is at a height of 49 meters. \n" ); document.write( "

Algebra.Com's Answer #777736 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!


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document.write( "Hi  
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document.write( "18.       4.9t2 + 24.5t - 117.6 = 0
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document.write( "19.           t = (-24.5 +( 24.5^2 + 4x4.9x117.6)^0.5)/ 9.8
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document.write( "               t = 3 seconds.
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document.write( "20.          4.9t2 + 24.5t - 49 = 0
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document.write( "              t = (-24.5 +( 24.5^2 + 4x4.9x 49 )^0.5)/ 9.8
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document.write( "Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation  (in our case ) has the following solutons:
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document.write( "  For these solutions to exist, the discriminant  should not be a negative number.
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document.write( "  First, we need to compute the discriminant : .
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document.write( "  Discriminant d=1560.65 is greater than zero. That means that there are two solutions: .
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document.write( "    Quadratic expression  can be factored:
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document.write( "  Again, the answer is: 1.53112887414928, -6.53112887414928.\n" );
document.write( "Here's your graph:
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