document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1162208>Question 1162208</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Daniel does a cannonball into the water.  He hits the water with a speed of 12.0 m/s.  The buoyant force of the water causes a constant acceleration of  8.00 (m/s)/s.  This slows him down until he stops.  Then, it pushes him back to the surface.  How long is he under the water?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #785971 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52750)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=785971\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .\r<BR>\n" );
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document.write( "This problem, as it is formulated in the post, is absolutely non-physical,\r<BR>\n" );
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document.write( "and I will explain it to you right now, why it is so.\r<BR>\n" );
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document.write( "It is true that for the human body, the buoyant force is close the the weight.\r<BR>\n" );
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document.write( "The weight makes free fall acceleration of about 9.8 m/s^2;\r<BR>\n" );
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document.write( "the buoyant force in this problem makes deceleration of 8 m/s^2, \r<BR>\n" );
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document.write( "and it is close to be true.\r<BR>\n" );
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document.write( "But if even the buoyant force would be equal to the weight, the body would be still continue <BR>\n" );
document.write( "to move vertically down in the water uniformly at the speed of 12.0 m/s.\r<BR>\n" );
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document.write( "But in reality, it does not happen.\r<BR>\n" );
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document.write( "Why ?\r<BR>\n" );
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document.write( "Because there is a THIRD FORCE, which is not accounted in the problem.\r<BR>\n" );
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document.write( "This force is DRAG of the water.\r<BR>\n" );
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document.write( "It produces the major deceleration to the falling body, in this case.\r<BR>\n" );
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document.write( "The resume is that this problem <U>has no right to exist</U>,\r<BR>\n" );
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document.write( "since it contradicts to both common sense and observed facts.\r<BR>\n" );
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document.write( "It, probably, does not matter to you, who created this problem, \r<BR>\n" );
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document.write( "but in this case I care about next generation of students, who, probably, will read this post in the future . . . \r<BR>\n" );
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