document.write( "Question 1100672: An object is thrown upward at a speed of 77 feet per second by a machine from a height of 7 feet off the ground. The height h of the object after t seconds can be found using the equation h = -16t^2+77t+7.
\n" ); document.write( "When will the height be 62 feet?
\n" ); document.write( "When will the object reach ground? \n" ); document.write( "

Algebra.Com's Answer #715195 by ikleyn(52781) $\"\"$ $\"About$

You can put this solution on YOUR website!
.
\n" ); document.write( "

\r\n" );
document.write( "1)  When will the height be 62 feet?\r\n" );
document.write( "\r\n" );
document.write( "    Solve the equation h(t) = 62,  which is  -16t^2+77t+7 = 62.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    Find its roots (if they exist).  \r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "2)  When will the object reach ground?\r\n" );
document.write( "\r\n" );
document.write( "    It will happen when h(t) = 0,  or, which is the same, when\r\n" );
document.write( "\r\n" );
document.write( "    -16t^2+77t+7 = 0.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    Solve this quadratic eq-n and use its positive root.\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );