document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1005463>Question 1005463</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Using the formula h=-1/2gt^2+v(0)t+h(0) (the zero in the parens is lower/small beneath the letter) and g= gravitational constant and v = upward velocity from a starting height of h. <BR>\n" );
document.write( " 1a. What is the height after three seconds of a penny dropped from the roof of the a tall building about 1250 feet tall? <BR>\n" );
document.write( " 1b. After how many seconds does the penny hit the ground? <BR>\n" );
document.write( " 2. What is the height after three seconds of a ball thrown from the roof of a building about 495 feet tall and is tossed upwards with a velocity of 10m/s? <BR>\n" );
document.write( " 2b. After how many seconds does it hit the ground? <BR>\n" );
document.write( " Thanks in advance. I think I have the answers but want to check the work done. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #621732 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=621732\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> note when dropping an object from height, the initial velocity vo is 0.  G is 16 for this problem, since given values are in feet.<BR>\n" );
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document.write( "1a) h(3) = -8*3^2 + 0*3 + 1250 = 1178<BR>\n" );
document.write( "after 3 seconds, the penny is 1178 feet above the ground<BR>\n" );
document.write( "1b) 0 = -8t^2 +1250<BR>\n" );
document.write( "t^2 = 156.25 and t = 12.5<BR>\n" );
document.write( "after 12.5 seconds, the penny hits the ground<BR>\n" );
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document.write( "the height of the building is given in feet, so convert vo = 10 m to feet/s, vo = 32.8 feet<BR>\n" );
document.write( "2a) h(3) = -8*3^2 + 32.8*3 + 495 = 521.4<BR>\n" );
document.write( "after three seconds, the ball is 521.4 feet above the ground.<BR>\n" );
document.write( "2b) 0 = -8t^2 + 32.8t + 495<BR>\n" );
document.write( "t^2 -4.1t - 61.875 = 0<BR>\n" );
document.write( "t^2 -4.1t = 61.875<BR>\n" );
document.write( "t^2 -4.1t + 4.2025 = 4.2025 + 61.875<BR>\n" );
document.write( "(t - 2.05)^2 = 66.0775<BR>\n" );
document.write( "t - 2.05 = 8.128806801 = approx 10.2 <BR>\n" );
document.write( "in 10.2 seconds the ball hits the ground<BR>\n" );
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document.write( "here is the graph of 2b<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28300%2C+200%2C+-10%2C+12%2C+-2%2C+800%2C+-8x%5E2+%2B32.8x+%2B495%29 ALIGN=MIDDLE  ALT=\"graph%28300%2C+200%2C+-10%2C+12%2C+-2%2C+800%2C+-8x%5E2+%2B32.8x+%2B495%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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