document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1166888>Question 1166888</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A softball is thrown upward. Its path can be modeled by the equation: h(t) = -16t2 + 32t + 5. Where h is the height of the ball in feet, and t is the time in seconds.<BR>\n" );
document.write( "Calculate the height of the object 7 seconds after it leaves the ground.<BR>\n" );
document.write( "At what time will the object strike the ground again?<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 #791445 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52787)</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=791445\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
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document.write( "To calculate the height of the object 7 seconds after it leaves the ground,\r\n" );
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document.write( "simply substitute t= 7 into the given formula for h(t) and calculate.\r\n" );
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document.write( "You will get then\r\n" );
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document.write( "     h(7) = -16*7^2 + 32*7 + 5 = -555.\r\n" );
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document.write( "It means that at t= 7 seconds the ball will be much lower than the ground surface,\r\n" );
document.write( "which means that at t= 7 the formula DOES NOT work, actually.\r\n" );
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document.write( "At the time t=7 seconds the ball will be,  gm-m-m,  on the ground surface or somewhere else,\r\n" );
document.write( "but the given formula just does not work for this time moment.\r\n" );
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document.write( "To answer the second question, you should solve this equation\r\n" );
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document.write( "    h(t) = 0 = -16*t^2 + 32t + 5 = 0.\r\n" );
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document.write( "I leave it to you to solve it - it is a simple exercise.\r\n" );
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document.write( "The last notice is that the formula for h(t) works only till that moment,\r\n" );
document.write( "when the ball will reach the ground.\r\n" );
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document.write( "Is everything clear to you from my explanation ?\r<BR>\n" );
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document.write( "In this site, &nbsp;there is a bunch of lessons on a projectile thrown/shot/launched vertically up\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/word/travel/Problem-on-a-projectile-moving-vertically.lesson>Problem on a projectile moving vertically up and down</A>\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/word/travel/Problem-on-projectile-shooted-vertically-upward.lesson>Problem on an arrow shot vertically upward</A>\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/word/travel/Typical-problems-on-an-projectile-moving-vertically-up-and-down.lesson>Problem on a ball thrown vertically up from the top of a tower</A> \r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/word/travel/Problem-on-a-toy-rocket-launched-vertically-up--from-the-top-of-a-platform.lesson>Problem on a toy rocket launched vertically up from a tall platform</A>\r<BR>\n" );
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document.write( "Consider these lessons as your textbook, &nbsp;handbook, &nbsp;tutorials and &nbsp;(free of charge) &nbsp;home teacher.<BR>\n" );
document.write( "Read them attentively and learn how to solve this type of problems once and for all.\r<BR>\n" );
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document.write( "Also, &nbsp;you have this free of charge online textbook in ALGEBRA-I in this site\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.\r<BR>\n" );
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document.write( "The referred lessons are the part of this textbook under the topic \"<U>Projectiles launched/thrown and moving vertically up and dawn</U>\".\r<BR>\n" );
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document.write( "Save the link to this online textbook together with its description\r<BR>\n" );
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document.write( "Free of charge online textbook in ALGEBRA-I<BR>\n" );
document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r<BR>\n" );
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document.write( "to your archive and use it when it is needed.\r<BR>\n" );
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document.write( "Happy learning (!)\r<BR>\n" );
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