document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=166564>Question 166564</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/9780073533490/algebrahomeworkh>ELEMENTARY AND INTERMEDIATE ALGEBRA</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> A ball is dropped from a height of 64 feet. Its height above the<BR>\n" );
document.write( "earth in feet is given by h(t )= 16t^2+64, where t is the<BR>\n" );
document.write( "number of seconds after it is dropped.<BR>\n" );
document.write( "a) Find h(1).<BR>\n" );
document.write( "b) How long does it take the ball to fall to the earth? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #122763 by </B><A HREF=/tutors/aboutme.mpl?userid=kevin6789><B>kevin6789(2)</B></A><img src=\"/images/stars/iconNewId_16x16.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=kevin6789><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=122763\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Part a:\r<BR>\n" );
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document.write( "h(t) = -16t^2 + 64<BR>\n" );
document.write( "h(1) = -16(1^2) + 64 <BR>\n" );
document.write( "h(1) = -16(1) + 64 <BR>\n" );
document.write( "ANSWER: h(1) = 48 feet\r<BR>\n" );
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document.write( "Part b:\r<BR>\n" );
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document.write( "The time it takes for the ball to hit the earth is the time from x=0 to the x intercept. \r<BR>\n" );
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document.write( "Since h is a function of time h(t), All you need to do is set h=0.\r<BR>\n" );
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document.write( "0 = 16t^2 + 64   Now subtract 64 on both sides.<BR>\n" );
document.write( "-64 = -16t^2   Now divide both sides by -16.<BR>\n" );
document.write( "4 = t^2   Now square root both sides.<BR>\n" );
document.write( "2 = t\r<BR>\n" );
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document.write( "ANSWER: It takes 2 seconds for the ball to reach the ground.\r<BR>\n" );
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document.write( "Note: For you problem to make sense as a math problem, it MUST be -16t^2. This could be a copying error.\r<BR>\n" );
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document.write( "Kevin\r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );