document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=596212>Question 596212</A>: <I><SPAN STYLE=\"word-break: break-all;\"> set h=0Trying to solve this multiple part problem, I have tried using the quadratic equation, I don't think I'm putting the numbers in the right place.  I know the formula for height, not sure where to start.\r<BR>\n" );
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document.write( "Here's the problem:  Guns on a battleship must fire their charges many miles.  In order to do this the charge must be fired high up into the sky. Suppose that one such gun shoots a charge so that its initial height above the water is 50 ft and its initial upward velocity is 1000 ft/ sec.<BR>\n" );
document.write( "1. How many seconds after it was shot will the charge hit the ocean?<BR>\n" );
document.write( "2. Fifty seconds after being fired, how high above the water will the charge be?<BR>\n" );
document.write( "3. How many seconds after it was shot will the charge first be 2000 ft high?<BR>\n" );
document.write( "4. How many seconds after it was shot will the charge next be 2000 ft high?<BR>\n" );
document.write( "5. What is the maximum height that the charge will reach?<BR>\n" );
document.write( "6. How high above the water will the charge be in 10 seconds? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #377626 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=377626\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> (height) = -(half the gravitational acceleration times the time squared) + (initial velocity times the time) + (initial height)\r<BR>\n" );
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document.write( "h = -16t^2 + 1000t + 50\r<BR>\n" );
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document.write( "the max height is on the axis of symmetry ___ t = -1000 / [2(-16)] = 125/4<BR>\n" );
document.write( "___ substitute the time into the equation to find the height\r<BR>\n" );
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document.write( "the quadratic formula is ___ <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "remember that the equation must equal zero to use the formula<BR>\n" );
document.write( "___ you may have to subtract the height from the expression to accomplish this\r<BR>\n" );
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document.write( "1. set h=0 in height equation, use quadratic formula to solve\r<BR>\n" );
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document.write( "2. (and 6) plug time into height formula\r<BR>\n" );
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document.write( "3. (and 4) height is 2000, but equation must equal zero to use quadratic formula (see above comments)\r<BR>\n" );
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document.write( "5. see above comments </SPAN>\n" );
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