document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=763757>Question 763757</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Help please! I'm so confused by this problem... \r<BR>\n" );
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document.write( "if an object is thrown vertically upward with an initial velocity of v, from an original position of s, the height h at any time t is given by: h=-16t^2+vt+s<BR>\n" );
document.write( "(where h and s are in ft, t is in seconds and v is in ft/sec)\r<BR>\n" );
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document.write( "a package is thrown downward with an initial velocity of -5ft/sec from a helicopter at 300 ft.<BR>\n" );
document.write( "a) what is the height of the package in 2 sec?<BR>\n" );
document.write( "b) how long does it take to hit the ground?   </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #464997 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><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=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=464997\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> f an object is thrown vertically upward with an initial velocity of v, from an original position of s, the height h at any time t is given by: h=-16t^2+vt+s<BR>\n" );
document.write( "(where h and s are in ft, t is in seconds and v is in ft/sec) <BR>\n" );
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document.write( "note that an object thrown upward would have a positive value for the initial velocity (v)....in our case the object is thrown downward so the value for v is negative.<BR>\n" );
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document.write( "a) what is height after 2 seconds?<BR>\n" );
document.write( "h = -16*t^2 +v*t + s<BR>\n" );
document.write( "h = -16*(2^2) -5*2 + 300<BR>\n" );
document.write( "h = -64 -10 +300<BR>\n" );
document.write( "h = 226 feet after 2 seconds<BR>\n" );
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document.write( "b) how long does it take to hit the ground?  that is h=0<BR>\n" );
document.write( "0 = -16t^2 -5t + 300<BR>\n" );
document.write( "divide by -1 and we get<BR>\n" );
document.write( "0 = 16t^2 +5 - 300<BR>\n" );
document.write( "use quadratic formula<BR>\n" );
document.write( "t = (-5+sqrt(25-4*16*-300)) / 32 = 4.18<BR>\n" );
document.write( "t = (-5-sqrt(25-4*16*-300)) / 32 = -4.49<BR>\n" );
document.write( "t reaches the ground in 4.18 seconds<BR>\n" );
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