document.write( "Question 1004984: the distance d, in feet required for a vehicle traveling at r mi/h to come to a stop is given approximately by d=0.05r^2 + r. If an automobile in a 55 mi/h speed zone is required 240 feet to stop, was its speed within the legal limit? \n" ); document.write( "
Algebra.Com's Answer #621319 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
the distance d, in feet required for a vehicle traveling at r mi/h to come to a stop is given approximately by d=0.05r^2 + r.
\n" ); document.write( "---------------------------------------------------
\n" ); document.write( "If an automobile in a 55 mi/h speed zone is required 240 feet to stop, was its speed within the legal limit?
\n" ); document.write( "---------------------
\n" ); document.write( "Solve for \"r\"::
\n" ); document.write( "0.05r^2 + r - 240 = 0
\n" ); document.write( "-------
\n" ); document.write( "Use the Quadratic Formula to get::
\n" ); document.write( "r = [-1 +- sqrt(1-4*0.05*-240)]/(2*0.05)
\n" ); document.write( "-----
\n" ); document.write( "r = [-1 +- 7]/0.1
\n" ); document.write( "-----
\n" ); document.write( "Acceptable answer::
\n" ); document.write( "r = [6/0.1] = 60 mph
\n" ); document.write( "----
\n" ); document.write( "Answer: No
\n" ); document.write( "--------
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "------------\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );