document.write( "Question 161504: 1) The Path of a falling object is given by the function s=-16t^2+v^o t+s^o where v^o represents the initial velocity in ft/sec and s^o represents the initial height in feet.\r
\n" ); document.write( "\n" ); document.write( "A) If a rock is thrown upward what an initial velocity of 64 feet per second from the top of a 25-foot building, write the height (S) equation using this information.
\n" ); document.write( " I got s=-16t^2+64t+25\r
\n" ); document.write( "\n" ); document.write( "B) How high is the rock after 1 second?
\n" ); document.write( " I got s=-16*1^2+64*1+25 so s=73\r
\n" ); document.write( "\n" ); document.write( "The questions I need the help on is C)& D)\r
\n" ); document.write( "\n" ); document.write( "C) After how many seconds will the graph reach maximum height?\r
\n" ); document.write( "\n" ); document.write( "D) What is the maximim height?
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Algebra.Com's Answer #118960 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Note: I'm replacing \"s\" with \"y\" and \"t\" with \"x\" to get the equation \"y=-16x%5E2%2B64x%2B25\"\r
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\n" ); document.write( "\n" ); document.write( "To answers questions C and D, we need to find the vertex. Remember, the vertex represents the highest/lowest point.\r
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\n" ); document.write( "\n" ); document.write( "In order to find the vertex, we first need to find the x-coordinate of the vertex.\r
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\n" ); document.write( "\n" ); document.write( "To find the x-coordinate of the vertex, use this formula: \"x=%28-b%29%2F%282a%29\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-b%29%2F%282a%29\" Start with the given formula.\r
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\n" ); document.write( "\n" ); document.write( "From \"y=-16x%5E2%2B64x%2B25\", we can see that \"a=-16\", \"b=64\", and \"c=25\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-%2864%29%29%2F%282%28-16%29%29\" Plug in \"a=-16\" and \"b=64\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-64%29%2F%28-32%29\" Multiply 2 and \"-16\" to get \"-32\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=2\" Divide.\r
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\n" ); document.write( "\n" ); document.write( "So the x-coordinate of the vertex is \"x=2\". Note: this means that the axis of symmetry is also \"x=2\".\r
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\n" ); document.write( "\n" ); document.write( "Now that we know the x-coordinate of the vertex, we can use it to find the y-coordinate of the vertex.\r
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\n" ); document.write( "\n" ); document.write( "\"y=-16x%5E2%2B64x%2B25\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"y=-16%282%29%5E2%2B64%282%29%2B25\" Plug in \"x=2\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=-16%284%29%2B64%282%29%2B25\" Square \"2\" to get \"4\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=-64%2B64%282%29%2B25\" Multiply \"-16\" and \"4\" to get \"-64\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=-64%2B128%2B25\" Multiply \"64\" and \"2\" to get \"128\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=89\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "So the y-coordinate of the vertex is \"y=89\".\r
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\n" ); document.write( "\n" ); document.write( "So the vertex is .\r
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\n" ); document.write( "\n" ); document.write( "Since the vertex is , this means that \"x=2\" and \"y=89\". \r
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\n" ); document.write( "\n" ); document.write( "So at 2 seconds, the object is at the highest point of 89 feet.\r
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